As Brussels prepares to appoint a new commission president, it is revisiting the question of just how the post should be filled.

In 2014, the Spitzenkandidat - or lead candidate - process was informally adopted - moving the decision out of European Council back rooms and into parliament. The post had to go to the party with the most seats.

" I think it was a very welcomed innovation to actually put forward candidates from all different parties for the position of Commission President," says Petro Fassoulas, Secretary General of European Movement International. "And I hope that is going to continue. To improve it would be great to have primaries: that each European party can put forward their own candidate after a selection process that is open and transparent, and then make sure that everybody that participated in it endorses the candidate that eventually will becomes president of the Commission".

If the system holds, rumoured frontrunners for the post include Michel Barnier and Pierre Moscovici of France, and Marghrete Verstager of Denmark.

The European Parliament says it won't endorse anyone appointed by the Council if they are not a top party candidate put forward ahead of the 2019 parliamentary elections.

Current Commission President Jean-Claude Juncker, who is due to step down next year, will make an announcement about the process on Wednesday (February 14).