The decision, approved in a resolution by the Party of European Socialists at a convention in Lisbon, increases the likelihood that other major parties will similarly commit to the so-called Spitzenkandidat process, which is intended to make European elections more democratic and give voters greater input.

The process, first adopted for the 2014 elections, resulted in Jean-Claude Juncker, a former prime minister of Luxembourg being selected as the candidate of the center-right European People’s Party (EPP), over his socialist rival, Martin Schulz, then a German member of the European Parliament.