BUCHAREST - Romania's ruling coalition of centre-right Liberals and leftist Social Democrats will run on joint lists in the European Parliament election on June 9, their leaders said, in a bid to stem the rise of the ultra-nationalist opposition party AUR.

However the two governing parties would still field their own separate candidates in local elections, which under their pact agreed late on Wednesday would also take place on June 9.

Opinion polls suggest that the Social Democrats (PSD) are voters' first preference, while the Liberals (PNL) would struggle to win second place against AUR.

"We decided to have an electoral alliance for the European election," PSD leader and Prime Minister Marcel Ciolacu said in a statement.

"No matter how we try to package it, it is clear that only the two biggest parties can face an extremist wave. Neither of the two political forces can go at it alone."

AUR, which swept into parliament for the first time in the last national election in 2020, has seen its support continue to rise as cost of living pressures and health and energy crises have eroded Romanians' trust in state institutions.

The government is struggling to keep public finances in check and implement reforms needed to retain access to European Union recovery and development funds.

As well as the local and EU elections, Romanian voters are also set to choose a new parliament and president this year.

Opinion surveys suggest the two ruling parties are likely to secure another majority in the parliamentary vote, which is expected to take place in December.

Local mayors are vital for parties in getting the vote out in parliamentary elections, handing an advantage to whichever parties win most mayors.

The party leaders said they would probably bring forward the date of Romania's presidential election to September from late November. They said they would also discuss a common strategy for the parliamentary and presidential elections. REUTERS