However, dissatisfaction with public policy and European Union frustrations will undermine her efforts to stay the course, founding member of the AfD, Frank-Christian Hansel, told CNBC. The latest INSA poll released Tuesday shows the CDU and its sister Christian Social Union (CSU) party gaining 37 percent, a notable lead on the second- and third-largest parties, the Social Democratic Party (SDP) and the anti-immigration Alternative for Germany (AfD), which are forecast 25 percent and 10 percent respectively. Still, the CDU will have to form a coalition to gain a parliamentary majority.

"The problems are getting so big with the migration crisis etc that this next government will not be in power for the full four years," Hansel said over the phone, insisting that Merkel's efforts to appease all voters are unsustainable amid rising European pressures.

Polling suggests that the AfD will win above the five percent minimum voter threshold needed to enter into parliament. This will be the first time that a populist right-wing party, which counts a number of right-wing extremists among its members, has done so since the end of World War II. It marks a sudden rise in popularity for the party which launched in just 2013.