Officials expect the spitzenkandidat vote will be carried with a significant majority | John Thys/AFP via Getty Images MEPs set to bolster ‘Spitzenkandidat’ process for EU top job Plan puts parties in pole position to pick next Commission president.

MEPs will vote Tuesday on a proposal to reject any candidate for the European Commission presidency if he or she does not have the official backing of a party political grouping.

The proposal before the European Parliament's Constitutional Affairs Committee — which officials expect will be carried with a significant majority — is a vote of confidence in the so-called Spitzenkandidat or leading candidate process.

The specific process does not have any official status in the EU treaties, but it was first used in 2014 to democratize a system that had hitherto allowed national leaders of the largest countries to dole out top EU jobs via backroom deals.

Under the process, the Commission presidency goes to the party grouping with the most MEPs. By linking the top job in Brussels to the parliamentary election, the idea was to confer democratic, quasi-electoral legitimacy on the position of Commission president.

The committee will vote Tuesday on the provision, included in a report “on the Revision of the framework agreement on relations between the European Parliament and the Commission,” as a way to institutionalize the Spitzenkandidat process.

The European Parliament “will be ready to reject any candidate in the investiture procedure of the Commission president who was not appointed as a Spitzenkandidat in the run-up to the European elections,” according to a compromise amendment seen by POLITICO. That means anyone wishing to replace Jean-Claude Juncker, once his term of office ends in 2019, would have to have a stamp of party approval to stand a chance.

The purpose of the vote is to put pressure on the European Council (made up of EU leaders) who may wish to backtrack on the Spitzenkandidat process in favor of a more opaque system for selecting the Commission president that gives them more behind-the-scenes power. Council President Donald Tusk has said the Spitzenkandidaten process will be discussed at a leaders’ summit on February 23.

French President Emmanuel Macron has been a vocal advocate of the process, saying in a recent speech that those who defend it should go further and have “real European elections.” On Monday, the European Commission's spokesperson, Margaritis Schinas, said the Commission viewed the system as a “success.”