Britain risks signing up to the worst possible Brexit deal, Theresa May's former chief of staff has warned as it emerges several Cabinet ministers want freedom of movement to effectively continue after Britain leaves the European Union.

Writing for the Telegraph, Nick Timothy tells the Prime Minister she must urgently harden her negotiating strategy, adding: "The time for playing nice and being exploited is over".

Mr Timothy, one of Mrs May's closest allies, says she has been "undermined" by Parliament and her own Cabinet and now risks being pushed into the worst possible outcome.

He accuses Greg Clark, the Business Secretary, of making the case for free movement. He says Philip Hammond, the Chancellor, has "blocked meaningful no-deal planning".

"This is ridiculous, and it has to stop," Mr Timothy writes. "The EU showed last December – when the talks faltered over Northern Ireland – that they want a deal. But they want a deal on the best terms for them, and the very worst for Britain. As things stand, they might well succeed."

He adds: "There is little point complaining, but we should listen and our strategy should change... The time for sincere cooperation with a partner that does not want to sincerely cooperate is over: we must toughen up."