Leaders of the main political groups in the European Parliament on Thursday (12 June) told EU council chief Herman Van Rompuy to nominate Jean-Claude Juncker as the next EU commission president or face an "institutional crisis".

Van Rompuy received the group leaders separately in his EU council office throughout the day.

Student or retired? Then this plan is for you.

All groups, except for the British Conservative-dominated ECR said EU leaders should nominate Juncker or the EP will veto any other candidate.

"Our core message is that there is a broad majority for Juncker in the EP and we expect Van Rompuy to propose him to EU leaders on 27 June," centre-right EPP group leader Manfred Weber said in a press conference after meeting Van Rompuy.

He said any other name coming out of the council would go against the promise made to voters that the top candidate (Spitzenkandidat) of the party who wins the elections becomes commission president.

"This is not just about filling posts, this is about democratisation, about bridging the gap between citizens and EU institutions. The European Parliament should be where the future of Europe is decided, not in rooms behind closed doors," Weber said.

He said it was important to show Europe is capable of getting its act together and sticking to the envisaged calendar - council nomination of Juncker on 27 June, vote in the EP on 15 July.

"We have no interest in a conflict, but certain members of the council should be aware of the risks," he said, in reference to Britain, Sweden, Hungary and the Netherlands who oppose the Spitzenkandidat system.

Grand coalition

The EPP is set to start negotiations on a grand coalition-type of agreement with the Social-Democrats and share the EP president mandate as they have in the outgoing legislature, Weber added.

The Social-Democrats are not unconditionally supporting Juncker, but will vote for him if their policy demands are reflected in his policy programme.

"We reiterate that Jean-Claude Juncker – as the candidate of the largest group in the European Parliament – must have the right to be the first to seek a majority in the European Parliament, through proposing an adequate work programme," outgoing S&D chief Hannes Swoboda said in a press statement.

The reasoning behind the S&D support for Juncker is that if he is not nominated, it will be much harder to push for left-leaning priorities and to get posts within the EP and the EU commission.

"It is a basic principle of democracy that the European Commission must represent the balance of the European Parliament, where the EPP has a slight lead and the S&D Group is the second largest group," Swoboda said.

A spokeswoman for the S&D group said it will be member states' fault if the process gets delayed.

"It's the council who delayed everything by a month. We would have liked Juncker to start negotiations on his programme earlier, but he prefers to wait for a mandate from the council. If he comes forward with proposals we can agree to, there is no opposition in principle to Juncker," S&D spokeswoman Celine Bayer told this website.

Britain still opposes

For Juncker to be nominated for the commission job, a "qualified majority" of member states is needed in the council.

Britain remains staunchly opposed to the idea of Spitzenkandidaten and to Juncker in particular because his views are considered too federalist.

A spokesman for the British government denied media reports that Cameron could agree to Juncker if his country got a super-commissioner post pooling economics, trade and energy in a so-called cluster portfolio.

The reorganisation of commission portfolios into bigger clusters reflecting policy priorities is a German idea aimed at meeting some of the British demands for reform.