Romania’s pro-European parties have reached a commitment to form a governing majority that cordons off the hard right and potentially endorses a single candidate for a rerun of the country’s annulled presidential election.

The ruling leftist Social Democrats won the most seats in the parliamentary election on 1 December, which also resulted in three ultranationalist and hard-right groupings, some with overt pro-Russian sympathies, winning more than a third of seats.

The parliamentary ballot was sandwiched in between two rounds of a presidential election, during which the far-right Nato-critic Călin Georgescu emerged from relative obscurity to become the shock frontrunner.

That prompted accusations of Russian meddling before the country’s top court annulled the presidential vote on Friday and said the entire process would need to be rerun.

The new government will need to come up with a new calendar for the presidential election, likely in the first part of 2025.

The outgoing president, Klaus Iohannis, who will stay on until a new president is sworn in, will nominate a prime minister. The current legislative term ends on 21 December.

On Monday, the Social Democrats, their current coalition partners the centre-right Liberals, the opposition centrist Save Romania Union and the ethnic Hungarian party agreed to quickly form a pro-European government.

“In the coming days, the four parties and representatives of national minorities will work on a common governing programme based on development and reforms which will consider the priorities of Romanian citizens,” a joint statement said.

Analysts expect the four parties, which have clashed often on policy issues, will struggle to agree measures needed to lower the EU’s largest budget deficit at 8% of economic output.

Analysts, ratings agencies and Brussels have said tax increases are needed, which will further erode the parties’ support.

The parties also said they were considering supporting a single pro-European candidate in the presidential election, to boost their chances of winning against a wave of support for ultranationalists.

It was unclear whether Georgescu would be allowed to run again, with prosecutors investigating his campaign.