Romania's Constitutional Court on Monday validated the shock first-round result in the country's presidential election, setting the stage for a run-off vote on Dec. 8 that could upend its pro-Western orientation and undermine backing for Ukraine.

Romania’s top court ordered a vote recount in the first round of the presidential election, it said on Thursday, in a ruling observers said risked tarnishing the credibility of state institutions ahead of two more ballots.

Calin Georgescu, who had been widely dismissed as a fringe candidate, won the most votes on Sunday with 22.9 percent. He will face a more centrist opponent in the second round on Dec. 8.

Romanian centrist and leftist parties looked to have fended off a surge by the nationalist right in Sunday's parliamentary election, as attention turned to a top court ruling later on Monday on whether to annul the results of a presidential vote.

Romanians cast ballots Sunday in a parliamentary election sandwiched between a two-round presidential race, the first of which has plunged the European Union and NATO member into unprecedented turmoil following allegations of electoral violations and Russian interference.

Romania's ruling center-left Social Democrats were poised to secure the most votes in Sunday's parliamentary election, according to preliminary results published Monday.