PARIS (Reuters) - France's far-right Rassemblement National, leading the race for EU elections in France, will no longer sit with the Alternative for Germany (AfD) in the European Parliament after the AfD's top candidate said members of the Nazi SS force were "not all criminals".

The far-right AfD, running second in German opinion polls before June's elections, has come under harsh scrutiny after senior figures attended a meeting where deportation of immigrants was discussed, and over allegations that it harbours agents for Russia and China.

Last week, a German court ruled that domestic security services could continue to keep the AfD under surveillance as a potentially extremist party.

In an interview published last weekend, the AfD's leading election candidate, Maximilian Krah, told the Italian newspaper La Repubblica that "SS were not all criminals".

The SS, or "Schutzstaffel", was the main paramilitary force of Adolf Hitler's Nazi party, and among its many roles took a leading part in the Holocaust, the slaughter of 6 million Jews and other groups targeted by the Nazis.

"The AfD has crossed lines that I see as red," Jordan Bardella, head of the Rassemblement National candidate list, said during an election debate on the French television channel LCI.

He added that the RN would build "new alliances" after the election, aiming to be part of the largest possible group in parliament.

Polls suggest that nationalist and eurosceptic parties will win a record number of votes in June. Voters are expected to punish mainstream parties for failing to shield households from high inflation, curb immigration or deliver adequate housing and healthcare.

The far-right parties in the European parliament are currently split between the European Conservatives and Reformists (ECR), whose de facto leader is Italian Prime minister Georgia Meloni, and the Identity and Democracy (ID) group, spearheaded by the RN, and including the AfD.

(Reporting by Benoit Van Overstraeten; Editing by Kevin Liffey)