European leaders launched a summer of wrangling over their union's political direction on Tuesday with a clash over nominations for Brussels' top job.

After dinner in Brussels, Germany's Chancellor Angela Merkel left saying she stood by her center-right group's candidate to lead the European Commission for the next five years.

"We stand by our lead candidate, the EPP (European People's Party) candidate, that is Manfred Weber. Others stand by their candidate, which is obvious," Merkel told reporters.

"We have responsibility towards our voters, and we will have to wait and see. It's too early to speak about this. Everyone needs to show tolerance and a willingness to engage in compromise."

But President Emmanuel Macron of France said the shifting political balance in the European Parliament after last week's election had broken the "prison" of the candidacy process.

"The key is that the people in the most sensitive posts share in our project and are as charismatic, inventive and competent as possible," he said.

"Everyone will have to move, and we are going to have build a consensus. In this framework the role of France, having broken out of the prison of spitzenkandidats, is to build a dynamic and credible movement, behind a project."

The president of the European Council, Donald Tusk, will now go away and try to draw up a list of nominees for top EU roles that a majority of leaders could get behind at a June 21 summit.

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If they fail find consensus, the debate will drag on, as it did in 2014, when it took several summits to agree on all the top jobs.

Alongside the Commission role, the leaders also have to choose a new Council president, a foreign policy chief, a speaker for the European Parliament and a central bank director.

Gender balance

Macron also told reporters, "It is important for me to have gender balance, that we name two men and two women."

He pushed against Weber, listing EU competition commissioner, Denmark's Margrethe Vestager, the bloc's Brexit negotiator, center-right Frenchman Michel Barnier, and Dutch Social Democrat Frans Timmermans as appropriate candidates.

Merkel said Macron needed to be realistic and take into account the fact that the EPP, which has nominated Weber for the Commission, would remain the biggest group in the new chamber.

Spain and Sweden backed Timmermans, while Ireland and Croatia spoke for Weber. Luxembourg and Slovenia supported Vestager, one of few women in the running.

"Gender balance means at least two women," said the summit chairman, Donald Tusk, who will now negotiate between capitals to come up with a list of names for approval by the 28 leaders.

Eastern capitals demanded geographical balance in awarding the prominent Brussels roles. Poland and Hungary would strongly oppose Timmermans as he led the EU's rule of law probes against them in his current Commission vice-president role.

Unanimity is not required, though it is hard to see a candidate succeeding against the will of more than just a handful of leaders, as that would risk damaging their future cooperation and stalling the EU's decision-making.

Dutch Prime Minister Mark Rutte, also mooted as a possible contender in the obscure recruitment process, said Tuesday's meeting was about "content rather than people," with focus on policy priorities, including climate change and migration.

Merkel and Macron are due to hold more talks in the German town of Aachen on Thursday, but one country already bound to see its EU representation diminished is Italy.

Rome now holds three of the bloc's top five jobs, but its Eurosceptic swing and debt problems have left it isolated in the EU, with Spain seeking to claim the space.

(With input from AFP, Reuters)