This would mean that almost as many homes blighted by negative equity as in the early 1990s after the last housing crash. The data, by mortgage administrators Homeloan Management Limited (HML), was based on 250,000 mortgage accounts across the country. It shows that home owners in Northern Ireland and the North West of England are likely to be worst hit by further property price falls.

With this price fall, one in three home owners in Northern Ireland could be trapped by negative equity. Not surprisingly, this problem will adversely affect those under 40, who have moved onto the property ladder more recently. HML's chief finance officer Neil Warman said: "This analysis show just how vulnerable UK households are to a continuing fall in house prices. Since their peak before the onset of the credit crunch, house prices have fallen by nearly 18 per cent and, although there's considerable variation in future forecasts, a number of analysts are saying we need to brace ourselves for further falls."

Nick Hopkinson, the director of PPR Estates, said, "Our company has had relatively few distressed inquiries from London sellers as a result of the unique dynamics in the capital." But he said this sentiment had changed over the past few months, a trend particularly noticeable in areas hit by the recent riots - such as Lewisham, Croydon, Walthamstow and Tottenham.

"In the areas we have seen buyers withdrawing. We are also aware of international buyers pulling back from investment purchases as a result of a loss of confidence in the 'safe haven' investing benefits of London. As we move into autumn I fear this may prove to be the catalyst that bursts the unsustainable property bubble that built up over the last few years."

PPR Estates said that in the regions negative equity was a growing problem for many home owners. A year ago it was able to help more than 15pc of the "distressed" sellers outside London who contacted the company. Now it was able to help less than 10pc because they market price of their property was less than the value of their mortgage.

No date has been fixed for the strike, but Mr Serwotka said it was likely to be in the middle or end of November. The Government's pre-Budget report is being announced on November 29. Officials suggested that as many as 10 unions might support the industrial action. The scale would dwarf the 24-hour stoppage in June when an estimated 200,000 went on strike.

Last night Mr Serwotka and the leaders of other public sector unions were meeting Francis Maude, the Cabinet Office minister, to discuss pension reforms. He said: "On plans to make people work longer, pay more and receive less they have not moved one jot."

The People's Daily, the main paper of China's ruling Communist Party, said the United States should excise the "cancer" of the law which authorizes Washington's sale of weapons to the self-ruled island of Taiwan that China considers its own territory. Taiwan's biggest ally and arms supplier, the United States is committed under a 1979 law to supply it with the weapons it needs to maintain a "sufficient self-defense capability."

Taiwan hopes to buy 66 late-model F-16 aircraft from the United States, a sale potentially valued at more than $8 billion and intended to phase out its remaining F-5 fighters. The arms sale debate has been building steam in the United States, with US Senator John Cornyn, a Republican from Texas, where Lockheed Martin Corp manufactures the F-16, saying killing the sale would cost valuable US jobs.

"At present, some madmen on Capitol Hill are making an uproar about consolidating and expanding this cancer," the People's Daily said in a commentary, adding these politicians were "wildly arrogant." "If these crazy ideas come to fruition, what kind of predicament will Sino-US relations find themselves in?" the paper wrote. The commentary appeared under a pen name "Zhong Sheng," a name suggesting the meaning the "voice of China," which is sometimes used to reflect higher-level opinion.

Police Commissioner Raymond Kelly said spot checks in the New York subway would be more frequent in coming days. President Obama called on the US to "redouble" anti-terror efforts. US TV network ABC News reports that three individuals - one a US citizen - entered the US in August aiming to carry out a terror attack. There was no confirmation about whether this information was linked to the threat detailed by US officials.

A service marking the 10th anniversary of the terror attacks in which almost 3,000 people died will be held on the site of the World Trade Center on Sunday. US President Barack Obama and former President George W Bush will attend the ceremony.

"Al-Qaeda has shown an interest in important dates and anniversaries. In this instance it is accurate that there is credible, specific but unconfirmed information" FBI Janet Fedarcyk said.

An investigation is looking into why the blackout spread from Arizona, where a piece of equipment was switched off. Extreme heat may be a factor. Officials say that a power line between Arizona and California was knocked out of service after an employee carried out a procedure at a substation in Arizona.

"There appears to be two failures here - one is human failure and the other is a system failure. Both of those will be addressed," said Damon Gross, a spokesman for APS. Daniel Froetscher, a vice-president at APS, told the Associated Press news agency it was "not a deliberate act". "The employee was just switching out a piece of equipment that was problematic," Mr Froetscher said.

In Los Angeles, trains were stopped because there was no power for lights and signalling, and a number of people had to be rescued from stuck elevators and theme park rides. California's two nuclear reactors were forced to shut down.

At Binghamton, New York, the wide river broke a flood record and flowed over retaining walls downtown as more than 8 inches of rain fell in some areas. Road closures effectively sealed the city off to outside traffic as emergency responders scrambled to evacuate holdouts who didn't heed warnings to leave neighborhoods.

"It's going to get worse," said Governor Andrew Cuomo, who urged residents to heed evacuate orders rather than wait until the flood danger is obvious. "By the time it looks that bad, you won't be able to leave, so leave and leave now," he said. Most of the people ordered to evacuate their homes were about 80 miles downstream in Wilkes-Barre, where the river was projected to crest later Thursday at 41 feet - the same height as the levee system, officials said. Residents were ordered to leave by 4 pm.

Wet weather followed by Hurricane Irene and its remnants have saturated the soil across the Northeast, leaving water no place to go but into already swollen creeks and rivers. After three days of living in shelters because of Irene, Edith Rodriguez, her mother and her sister spent Wednesday night at a high school outside Schenectady when the latest storm chased them from their home near the Mohawk River. "We just finished cleaning up after the flood from Irene," the 19-year-old said. "Now we have to start all over again."

About 240 other homes have been lost in other fires since Sunday, the service said. Despite hopes that the fire would be largely contained by Wednesday night, it remained 30% contained Thursday morning, she said. About 34,000 acres have been destroyed. The fire has killed at least two people. An elite search team is helping local officials scour the area for other potential victims. At least 5,000 people evacuated the area, officials said.

Authorities said Thursday they were allowing some people to return to their homes in areas where it was safe to do so. Officers were being repositioned to help keep order and make sure people did not enter closed-off areas. The Bastrop fire is one of scores that have been burning across the drought-stricken state. Wildfires have been scorching Texas for nearly 300 days. In the past week, the Texas Forest Service said it has responded to 176 fires over 126,844 acres. President Barack Obama called Governor Rick Perry to "express his concern for citizens of Texas impacted by the unprecedented fires."

The "big five" has told the EU foreign minister that she must set up a European "Operational HQ" by any means necessary, including a legal mechanism, created by the Lisbon Treaty that bypasses a British veto. William Hague, the Foreign Secretary, threatened in July to veto a proposed military HQ to "command and control" troops, including British forces, taking part in EU operations, such as the current antipiracy naval force off the coast of Somalia.

But in a confidential letter, dated September 2, foreign ministers from the five countries create a powerful alliance against an isolated Britain by pledging their "strong political will to continue" as a "matter of urgency". "France, Germany, Italy, Poland and Spain remain at your disposal to support your work in this regard," says the letter to Lady Ashton, seen by The Daily Telegraph. "We believe it remains the most comprehensive basis for further work on all the issues: capabilities, including civil-military planning and conduct capability, battle groups and EU/Nato relations."

Most controversially, the alliance instructs Lady Ashton to seek "structured co-operation" a legal route, never before used, to set up the HQ without Britain, with "tangible results" demanded by the end of the year. "We encourage you to examine all institutional and legal options available to member states including permanent structured co-operation to develop critical Common Security and Defence Policy capabilities, notably a permanent planning and conduct capability." "Structured co-operation" would allow countries to go it alone on the military HQ on the basis of a majority vote, bypassing Britain's veto to put British forces in EU battle-groups outside the command structure and creating a new rift in Nato.

In her proposals, Lady Ashton, urged that the European operational headquarters currently spread across Europe in Germany, France, Greece, Italy and Britain be united under one roof, with an EU military staff of 250 people. The move puts the EU foreign minister, a Labour peer, at odds with the British government and could lead to the worst rift in European foreign policy since the Iraq war in 2003.

British officials observe that European divisions over military operations, such as with Libya, will not be papered over by creating an expensive HQ. "Focusing energy and resources on a project which is essentially about symbolism represents a costly distraction from investment in the defence and civilian capabilities that are really required, and will do nothing to increase political will to act," said the spokesman.

German Chancellor Angela Merkel has long been accused of dragging her feet in the euro-zone debt crisis - and of shying away from the kind of greater European integration that many have been calling for. On Wednesday, however, she sang a different tune.

In a speech before German parliament, part of a general debate on the budget, Merkel made a plea for "more Europe" and said that to make Europe strong and lasting, "treaty amendments can no longer be taboo in order to bind the EU closer together." She also reminded her country that a strong Europe was in Germany's interest. "In the long term, Germany cannot be successful if Europe isn't doing well too."

It was unclear whether Merkel was referring to recent demands by Finance Minister Wolfgang Schauble for a new treaty which would hand far-reaching fiscal powers to Brussels or to her own 2010 demands for a Lisbon Treaty amendment strengthening deficit rules.

Merkel also said it was time to seriously consider installing a measure which would allow countries who violate European Union deficit rules to be brought before the European Court of Justice, the legal body that settles disputes between EU governments and institutions. It marked a return to her staunch position last summer that those who violate deficit rules must be automatically punished - a position she ultimately backed away from at the urging of French President Nicolas Sarkozy.

Merkel's speech came amid growing concerns in the European Union that sluggish implementation of austerity measures in Greece and inconsistent focus on exorbitant debt in Italy could put the common currency under yet more pressure.

The Constitutional Court in the southern city of Karlsruhe rejected, as expected, a series of lawsuits aimed at blocking German participation in emergency loan packages. Chancellor Angela Merkel hailed that decision as validation of her much-criticized euro zone policy. But the court also said her government must get approval from parliament's budget committee before granting such aid and appeared to rule out more radical solutions floated by Germany's European partners for solving the crisis, such as joint euro zone bonds.

"This was a very tight decision. But it should not be mistakenly interpreted as a constitutional blank check authorizing further rescue measures," the chief judge Andreas Vosskuhle told plaintiffs, government officials and members of parliament in the courtroom. The euro briefly rose against the dollar in response.

"Today's ruling should bring some relief to financial markets as a total chaos scenario has been avoided, but it should not lead to euphoria," said Carsten Brzeski, an economist at ING. Doubts about the willingness of countries like Italy and Greece to push through the austerity measures demanded by their partners have darkened the political mood in Germany and other northern European members of the 17-nation currency bloc.

Italy's center-right government promised on Tuesday to hike value-added tax as it bowed to market pressure for more action on its swollen debt and ignored mass street protests and strikes against its austerity measures. Merkel, in a speech to parliament following the court ruling, said a radical change in attitude was needed to resolve the crisis.

"I'm convinced that this crisis, if a great crisis of the western world is to be avoided, cannot be fought with a 'carry on' attitude. We need a fundamental rethink," Merkel said. "We must make it very clear to people that the current problem, namely of excessive debt built up over decades, cannot be solved in one blow, with things like euro bonds or debt restructurings that will suddenly make everything okay. No, this will be a long, hard path, but one that is right for the future of Europe," she told parliament.

Andrew Colquhoun, head of Asia-Pacific sovereign ratings at Fitch, told Reuters in an interview that China's local currency debt rating could face a downgrade over the next 12 to 24 months. "We expect a material deterioration in bank asset quality," he said. "If the problems in the banking system pan out as we expect or are even worse over the next 12 to 24 months, then that would incline us to take the rating downwards."

Fitch downgraded the outlook on China's long-term local currency debt to negative from stable in April because of concerns about the country's financial stability after a lending surge over the past two years. Fitch's China rating is AA minus, its fourth highest level.

China reported local government debt of 10.7 trillion yuan as of the end of 2010. More than 347 billion yuan in urban construction investment bonds were issued in the five years to 2010. Colquhoun also said there was a greater than even chance Fitch will downgrade Japan's credit rating because of the country's public debt, which is running at about twice the size of the $5 trillion economy.

France's Foreign Minister Alain Juppe on Wednesday accused Syria of carrying out "crimes against humanity". Speaking in Moscow, he said Syria could face further sanctions if it did not change course. More than 2,200 people have died in five months of protest.

The government insists that it has a reform programme in place, but opposition leaders say there can be no free and fair elections while the ruling Baath party is in power. They have also refused to negotiate while it continues to kill peaceful protesters. Speaking in Moscow during a press conference with his Russian counterpart Sergei Lavrov, Mr Juppe said: "The way [Syria has] suppressed the popular protests is unacceptable."

Meanwhile on Wednesday it was announced that Arab League Secretary-General Nabil al-Arabi would now visit Syria, after reports that Damascus had called off a planned trip. Mr Arabi would visit on Saturday, said the League's deputy leader, Ahmed Ben Helli. The League has called for an end to the violence and spoken of the Syrian people's legitimate aspirations for social and political reform. The League will meet to discuss Syria on 13 September.

The National Blood Service screens all donations for HIV and other infections. However, there is a "window period" after infection during which it is impossible to detect the virus. In the UK, a lifetime ban was introduced in the early 1980s as a response to the Aids epidemic and the lack of adequate HIV tests.

Most new HIV infections acquired in the UK are from men who have sex with men. Other at-risk groups, such as people who have been sexually active in high-risk countries, are banned from donating for a year. The lifetime ban has been questioned both on equality and medical grounds, in the light of developments such as improved blood screening tests which have reduced the size of the "window period" and reduced the risk of contamination. South Africa has introduced a six-month gap between sex and donation. It is a year in Australia, Sweden and Japan.

Research published at the end of last year suggested there was no significant increase in the risk of HIV infection after the change in the rules in Australia. The UK government's Advisory Committee on the Safety of Blood, Tissues and Organs has been reviewing policy.

The Terrence Higgins Trust, the UK's largest HIV and sexual health charity, says the arguments must be about public health, not discrimination. It states: "We believe any decision on the safety of the blood supply must be based on evidence and not on political lobbying or framing of it as purely an equalities issue."

George Little, the Pentagon press secretary, said the decision was not prompted by any specific terrorist threats but rather was a "prudent" acknowledgment that al-Qaeda leaders in the past have indicated a desire to strike again on September 11. "The 10th anniversary was mentioned in the documents seized in the Abbotabad compound," Little noted, referring to the May raid that killed al-Qaeda founder Osama bin Laden in his Pakistan hideout.

Little declined to elaborate on precisely what security levels had been imposed or how long they would endure. The request to raise the alert level was made by General Charles H Jacoby, Jr, chief of the US Northern Command, and approved by Defense Secretary Leon E Panetta. Most overseas bases were already operating with higher security precautions, Little said.