- German Chancellor Angela Merkel and Austrian Chancellor Sebastian Kurz, has served as leader of the European People’s Party.
- French President Emmanuel Macron has shown no indication of his support for Mr Weber.
- Her battle to protect consumers and make large firms pay earned her the wrath of US President Donald Trump last year.
It is all change at the heart of the EU, and the key role of Commission president is up for grabs as Jean-Claude Juncker prepares to pass the baton at the end of October. But who will take his place?
May elections have left the European Parliament more fragmented and the chances of reaching consensus more difficult.
Heavyweights France and Germany have already clashed over the role, which includes proposing new European laws and providing political guidance.
So who is in the running, based on what we know so far? There are official candidates – and some who are not yet candidates at all.
Manfred Weber, European People’s Party
The 46-year-old Bavarian, whose candidacy has been endorsed by prominent leaders such as German Chancellor Angela Merkel and Austrian Chancellor Sebastian Kurz, has served as leader of the European People’s Party (EPP) since 2014.
EU’s big two divided over Brussels’ top job
The EPP may be the biggest grouping in Parliament but it has lost ground in the elections and Mr Weber will have to secure the support of other groups if he is to win.
French President Emmanuel Macron has shown no indication of his support for Mr Weber, and with environmental issues coming to the fore and a surge in Green MEPs elected in May, it will not help that his centre-right colleagues have been accused of voting against climate change measures.
Margrethe Vestager, Liberals
A big name in Danish politics, Ms Vestager has spent the past five years as competition commissioner, spearheading EU anti-trust investigations that have ended in big fines for technology giants Google and Apple.
Her battle to protect consumers and make large firms pay earned her the wrath of US President Donald Trump last year, who is reported to have told Mr Juncker following news of the hefty fines: “Your tax lady, she really hates the US.”
Ms Vestager is certainly causing a buzz and the Liberal ALDE group gained ground in the elections, partly thanks to the arrival of President Macron’s party.
But the Liberals have fielded a slate of seven candidates for the EU job, and one Commission colleague says her choice is out of the question as she was not even a lead candidate.
Frans Timmermans, Party of European Socialists
Frans Timmermans has the wind in his sails, having led the Dutch centre-left Labour party to a dramatic, unexpected victory in the European elections, winning 19% of the vote on the back of a pro-European campaign.
Mr Timmermans is First Vice-President of the European Commission, helping to steer through EU legislation banning plastic straws and negotiating the EU’s deal with Turkey to reduce the flow of migrants.
He was lampooned in the run-up to the May vote by political opponents as Eurocrat “Hans Brusselmans”; but the negative message failed and the multi-lingual Labour leader took advantage of his election campaign to push for the Commission presidency.
He is widely disliked in Poland and Hungary for challenging their governments over rule of law.
Ska Keller of the Greens
After the Green surge in the May elections, her grouping is now the fourth biggest in Parliament and environmental issues have become key to the EU’s agenda over the next five years. In her home country, Germany, the Greens are currently leading in the opinion polls.
Ska Keller has already stood once as Green “Spitzenkandidat” (top candidate) in 2014, and is as focused on the rights of migrants as she is the plight of the environment. She has previously demanded that future EU agreements contain better protections for human rights.
She became a MEP in 2009 at the age of 27 and has said that, while she aims to represent everybody, young people in particular need a louder voice in Europe.
She has a master’s in Islamic Studies, Turkology and Jewish Studies and is social media savvy, posting regularly on Twitter to her more than 45,000 followers.
Against: Up against the other candidates, Ms Keller is likely to struggle to find the support of enough member states.
And as it is the member states who have the job of nominating a candidate for approval by the Parliament, they are more likely to go for one of the bigger names.