David Lammy, the shadow foreign secretary, told The Telegraph that Labor had been “clear about the red lines” it had set ahead of the talks with Brussels.
“I don’t think your readers are surprised by Labor’s commitment to high standards – the British people are committed to high standards,” he said.
“We want high standards on environmental protection. We want high standards on workers’ rights. This is nothing new, and we are not tearing up arrangements for that.”
Labour’s position on Brexit has come under intense scrutiny following Sir Keir’s incautious comments to a left-wing Canadian think tank last weekend.
His insistence that “we don’t want to move away” from Brussels was jumped on by senior Conservative Party members, who said it showed he had a secret agenda to rejoin the bloc.
He faced new pressure from within his own party to soften his stance on Brexit, with Sadiq Khan calling on him to prioritize “close alignment with the EU”.
The Mayor of London told Sky News: “It comes by looking at every sector in terms of the deal with the European Union, in terms of financial services.
“There has to be a closer alliance with the EU. However, that will mean negotiating the deal we currently have.
“You can’t bury your head in the sand, especially when there’s an option for a review in 2025, and pretend things are going well when they clearly aren’t.”
Rees-Mogg: Sir Keir wants to return to the European Union
It is the second time Sir Keir has faced Brexit woes in the space of a week, after he also faced a backlash over his immigration plans.
He was forced to confront accusations that his strategy to stop the boats would require Britain to take in tens of thousands of asylum seekers a year from the European Union.
Conservative strategists claim that the Labor leader’s difficulties show that he is starting to make strategic mistakes because he is forced to implement his policies.
Chris Clarkson, the Tory MP for Heywood and Middleton, said: “Sir Keir’s position on the EU, as on so many other things, depends entirely on who he talks to.”
Sir Jacob Rees-Mogg, the former Brexit opportunities minister, added: “Starmer does not want to deviate from Brussels at all, not at all. In fact, he just wants to rejoin.”
It comes after Ms Reeves pledged to change the law so that every major tax and spending decision made by Labor is analyzed by Britain’s financial watchdog.
The shadow chancellor said the policy aimed to avoid a repeat of the “catastrophic mistakes” made by Liz Truss in last year’s notorious mini-Budget.
Her plan is to create a “fiscal lock-in” where ministers are legally obliged to consult the Office for Budget Responsibility on tax reforms and permanent spending above a certain threshold.
George Osborne, the former Tory chancellor, backed Labour’s “sensible” proposals, arguing that Rishi Sunak would be “clever” to make changes himself.