The far-Right Alternative for Germany party (AfD) on Monday moved to expel one of its most controversial figures amid plunging public support.

The party’s ruling executive voted to expel Björn Höcke over comments he made last month in which he called for a “180-degree turn” in Germany’s attitude to the Second World War and an end to national guilt for the crimes of the Nazis.

The move threatened to split the party just months before elections in September in which it hoped to mount a serious challenge to Angela Merkel.

The decision to expel Mr Höcke is an unexpected U-turn and comes as voters appear to be deserting the party in the opinion polls.

Mr Höcke enjoys widespread support among the grassroots membership, and only last month the leadership agreed to let him remain in the party despite his comments, which attracted widespread public condemnation.

But since then the party has seen its support in the polls drop five points in just two weeks, from 15 per cent to 10 per cent.

“We think this step was necessary because, in such an important election year, the party must be united,” Frauke Petry, the party leader, said.

Mr Höcke had crossed the line of what is “democratically acceptable” with his comments, she said.