"I think if you look at Deutsche Bank, what John Cryan (Chief Executive, Deutsche Bank) is doing is trying to lead a very long march back to a sustainable model. They have got through a lot of harder stuff but there are still many mountains ahead." The bleak warning comes after Deutsche Bank, the country’s largest lender, is facing a huge fine of $14 billion (£11 billion) from the US Department of Justice for the mis-selling of residential mortgage-backed securities in the run-up to the 2008 financial crisis.

Mr Watt added: ”If the bank can remain solvent and the bail-in is not too severe then it is a bit like someone having a heart attack and the defibrillator is put on them and they recover. They are not well but the proportion between the moment when things are applied to them and their recovery is a big change for the individual." A settlement between the German bank and the US department is yet to be reached which is having a long-term effect on the bank, whose shares have plummeted 21 per cent since the start of the year.

But a deal could be struck as soon as Wednesday, according to reports. An insider said: “There is a good chance the case will be off the table before Christmas.” Deutsche Bank had been said to agree a settlement in the region of $4 to 5 billion, according to the specialist German financial publication Der Platow Brief, which also said that bank was looking to scrap bonuses and raise new capital.