Three votes by the European Parliament in recent years have exposed deep divisions between EU members from the wealthier west and the previously communist east of the bloc.
The Fidesz party of firebrand Hungarian Prime Minister Viktor Orban has been suspended from the European People's Party
Eurosceptic populists are projected to make gains in European Parliamentary elections in May but mainstream political groups ought to retain their majority, opinion polls suggest.
Three months from the European Parliament election, the assembly's dominant centre-right bloc has been weakened by a rift over how to handle Hungary's populist leader Viktor Orban.
The re-election of Hungary's Viktor Orban may have delighted populists, but the anti-immigration leader's triumph looks set to prolong the fractious EU-Budapest relationship.
Viktor Orban, a xenophobic populist whose changes to the electoral system and grip on the media have provoked criticism at home and abroad, is likely to win another term in office in election.