Keir Starmer’s charm offensive with the EU is failing to “cut through” despite being a Government priority, Brussels believes.

David Lammy became the first Foreign Secretary to attend the EU’s Foreign Affairs Council for two years, hailing his visit as a “historic moment” as he arrived for the meeting on Monday morning.

The trip, at the invitation of Josep Borrell, EU high representative for Foreign Affairs and Security Policy, follows the Prime Minister’s recent visit to Brussels where he pledged to move beyond Brexit and make the UK’s relationship with the EU work for the British people.

But European officials are understood to privately believe that the diplomatic efforts haven’t yet led to concrete changes in policies.

“It’s nice that they are visiting us and want to talk more, but we need substance,” an EU source told the i. “Britain doesn’t come up much here and won’t cut through when we have so much else on.”

Another European diplomatic source told i: “The EU side really appreciates the new tone coming from the UK Government, but there is still not much ‘flesh to the bone’ of the EU-UK reset.

“Officially no discussion on EU-UK relations is planned, but I could imagine everyone hoping that Lammy will present some outlines of what the UK wants.”

Sir Keir Starmer’s refusal to concede ground on a youth mobility scheme is seen by Brussels as an area where Labour is willing to realign with the bloc.

Brexiteers have warned such a move, however, would be the first step to taking the UK back into the EU’s orbit.

And Sir Keir is facing a split within his own party over the Government’s future relationship with the EU.

Chancellor Rachel Reeves on Monday slapped down Sadiq Khan’s hopes of discussing rejoining the single market.

The Mayor of London said: “The current Brexit deal we have comes up before review next year. I’m hoping, unlike last time, there will be closer alignment, rather than divergence.

“We should be looking at a whole host of issues and talking about them – whether it’s a youth mobility scheme, whether it’s seeing what we can do to bring people closer together.

“I think the reality is, in the short-term, we probably aren’t going to get back as members of the single market. But it’s something we shouldn’t be scared to talk about.”

But the Chancellor blasted back: “This is a Government that plans to stick to the manifesto we were elected on.

“We got a big majority at that election to implement what is in our manifesto, not to rewrite history and now say that we have a mandate to do something else. So our red lines are around the single market, the customs union and bringing back free movement, and we will stick to that manifesto.

“But we were also clear in our manifesto that we do want to reset relations and improve our trading relationships with our nearest neighbours and and trading partners.

“And at the moment, especially for small businesses that are the lifeblood of any economy, being able to import and export from countries that are nearest to us is unnecessarily burdensome and, as a result, many small businesses no longer export.”