PASSAU, Germany (Reuters) - The leader of the European Parliament’s main center-right bloc, which has threatened to expel Hungary’s ruling Fidesz party over anti-EU and anti-immigrant rhetoric, said on Wednesday signals from Hungarian Prime Minister Viktor Orban were not encouraging.

Manfred Weber, member of the Christian Social Union (CSU) and top candidate of the European People's Party (EPP) for the European elections, speaks at the party's traditional Ash Wednesday meeting in Passau, Germany, March 6, 2019. REUTERS/Michael Dalder

On Tuesday, German conservative Manfred Weber, the center-right European People’s Party (EPP) candidate to be EU Commission President, said Orban must apologize for his criticism of the EU or Fidesz could be suspended from the group.

A senior Fidesz member of the European Parliament said late on Tuesday his group would not accept conditions other European lawmakers set to remain part of the alliance.

“The signals coming from Viktor Orban and the Hungarian Fidesz party are not encouraging,” Weber told Reuters TV on the sidelines of a meeting of Bavarian conservatives in Passau.

“We have made several attempts at bridge building, but Hungary has not taken any steps or effort towards us,” he said.

Orban has long been at loggerheads with Brussels over his hardline stance on immigration and accusations - which he denies - that he is undermining the rule of law at home by imposing control over the judiciary, media and other bodies.

The feud is escalating ahead of European Parliament elections in May and is forcing a debate among European conservatives about how to deal with nationalists such as Orban.

The EPP has 217 lawmakers in the 750-strong EU legislature, 12 of them from Fidesz. It is expected to remain the biggest parliamentary group in the May elections, although likely weakened, opinion polls show.

Far-right, populist parties are expected to perform well.

“We are the European People’s Party, a party that stands for values and core convictions and we will not let anyone destroy this,” Weber said. “It is not about the number of delegates, it is about our values.”