Gianni Pitella, of the Group of the Progressive Alliance of Socialists and Democrats in the European Parliament | Patrick Seeger/EPA Pittella snubs Weber, highlighting end of grand coalition Socialist skips regular meeting with EPP leader.

Underscoring his wish to end the coalition with the conservative European People's Party group, Gianni Pittella, leader of the Socialist bloc in the European Parliament, said he would skip a meeting on Wednesday with Manfred Weber, chairman of the EPP.

A source from the Progressive Alliance of Socialists and Democrats (S&D) who is close to Pittella said the Italian MEP decided against attending the meeting, which has taken place on a regular basis for years, because “the coalition is over.”

Pittella is expected to be re-elected chairman of the Socialists in the Parliament on Wednesday, a week after he announced he would make a bid to succeed departing President Martin Schulz.

Sources in the S&D group say they expect a vast majority of MEPs to vote in favor of Pittella, who has led the 189-member group since 2014. If Pittella is elected president of the parliament on January 17, he would have to resign as chairman of the S&D, sources say.

Last week, Pittella announced he would run for the January presidential elections and end the current coalition between the main center-right and center-left groups of MEPs.

EU leaders have relied on the carefully calibrated “grand coalition” to pass significant legislation and manage a series of crises since 2014.

Pittella, who joined the Parliament in 1999, also said he would end austerity policies in the EU and move toward “more sustainable development,” telling reporters he was willing to work with all political groups “except right-wing extremists” to seek convergence around his candidacy.

On Wednesday, Pittella, Weber as well as Guy Verhofstadt, the leader of the liberal ALDE group, were meant to discuss, among other topics, the future presidential elections in January. Weber and Verhofstadt were both re-elected leaders of their groups earlier this month.

“If Pittella doesn’t deal with Weber on this, with whom is he going to deal?” said an EPP official.

Weber said last week he opposed Pittella’s wish to end the grand coalition. "To limit the influence of extremists in the European Parliament there is no alternative to cooperation between the EPP and the S&D groups,” Weber told POLITICO. “We are ready to continue this cooperation. It worked very well during the vote on the EU budget today, for example."

The EPP will elect its candidate for the presidential election on December 13. EPP sources say Weber is now exploring with other groups which of the three main EPP candidates is likely to appeal to other groups.

The candidates include former French cabinet minister Alain Lamassoure, former Slovenian Prime Minister Alojz Peterle and Mairead McGuinness, an Irish MEP.