Germany's anti-euro Alternative for Germany (AfD) party slipped two points to 4 percent in an opinion poll released on Wednesday after a leading member resigned last week due to an internal rift over whether to focus more on immigration.
It is the first time this year that the AfD, which has had a spate of successes in state elections over the past year, has fallen below the 5 percent threshold needed to enter parliament, said Forsa pollsters.
Hans-Olaf Henkel, an ally of party founder Bernd Lucke, quit last week saying the AfD, set up two years ago on an anti-euro ticket, would lose its way if the party's leaders did not settle their differences.
Lucke wants the AfD to focus on liberal economic policies, whereas other leading members of the party have scored points with voters by addressing fears about immigration. Some members have also moved closer to the grassroots anti-Islam movement PEGIDA.
The AfD fell just short of 5 percent in the 2013 federal election but since then has won seats in the European Parliament and four German state assemblies. It has poached support from Chancellor Angela Merkel's conservatives and the Free Democrats.
The AfD's performance in a vote in the northern state of Bremen on May 10 will be closely watched to see if the infighting has taken a toll on its support.
