Tensions boiled over at the election rally of Germany’s anti-euro party Alternative fuer Deutschland (AfD), when far-left activists attacked the leader on Saturday.
Bernd Lucke was pushed to the ground in the northern city of Bremen and one campaign worker was attacked with a knife.
It is the latest in a string of scuffles between the far-left and the party which is calling for the return of the deutsche mark.
Over in Berlin, 150 far-right nationalists protesting against a new home for asylum seekers were met by a 750 strong force of counter demonstrators.
The issue of refugees is proving a hot topic ahead of the elections in less than a month. Last week Chancellor Merkel warned against far-right extremism. Polls suggest she is likely to make a comfortable to return.