Sir Keir Starmer is heading to Brussels today for the first time as Prime Minister, as he sits down for a first bilateral meeting with Ursula von der Leyen, the chief of the European Commission.

The PM is under significant pressure from Ms von der Leyen and the EU to open discussions on a youth mobility scheme that would allow young people from the EU to live and work in the UK for a fixed period, and vice versa.

This comes as Sir Keir faces a growing split in his party over how to handle negotiations with the EU, with many c abinet ministers urging the PM to back down to Brussels over the scheme.

A significant proportion of the Labour Party is firmly pro-EU, including the prominent mayors of London, Sadiq Khan, and Greater Manchester, Andy Burnham, adding pressure on the PM.

However, the main opposition to the EU’s plans has come from the Home Secretary, Yvette Cooper, according to Politico. Ms Cooper could spark a huge Labour Party split, as she suggests that the scheme would send the wrong signal over migration.

According to a Home Office source, the Home Secretary believes the EU plan is simply “not compatible” with pledges to bring down net migration

The source dismissed claims that the temporary nature of the youth mobility should not count towards migration numbers, explaining: “They would still be part of the UK labor market.”

Mr Starmer has so far resisted the EU proposals, telling reporters last week that he had “no plans for a youth mobility scheme”.

There is growing frustration in Brussels that Labour has “no plan” for the EU despite pledging a reset in relations.

Mujtaba Rahman, the managing director for Europe at the Eurasia Group, said: “I’ve been taken aback by how frustrated both sides are actually. There’s a sense on the European side that Labour raised expectations in opposition.

“They’ve got a stonking majority and yet the government’s rhetoric on Europe seems very unambitious.

“There’s a real sense there is no plan.

“Senior officials on the European side are asking, what does Labour actually want to do?

“The suspicion is that the principals in the cabinet – Starmer, Cooper, Reeves, Thomas-Symonds – aren’t aligned.”

Senior European politicians have made it clear that without the scheme, the rest of the negotiations are pointless.

EU officials and analysts told the Guardian the scheme had become a “token of good faith” in the relationship.

During his meetings in Brussels, the prime minister will also meet Charles Michel and Roberta Metsola, the heads of the European Council and the European Parliament.