Donald Trump offered Theresa May a free trade deal when he visited Britain four months ago but the Prime Minister turned him down, a former minister has claimed.

Owen Paterson revealed Mr Trump's aides told him that the President had offered a free trade deal "on a plate" when he met with Mrs May at Chequers in July but was told the UK "wasn't ready".

The revelation came as Mr Trump suggested Mrs May’s Brexit agreement could threaten a US/UK trade deal, saying the withdrawal plan “sounds like a great deal for the EU”.

Mrs May was forced to reject the bleak assessment during a visit to Wales on Tuesday, insisting Downing Street had “already been talking” to the US “about the sort of agreement we could have with them in the future.”

In a move that will heap further embarrassment on the Prime Minister, Mr Paterson, the former Environment Secretary, told the Telegraph: "When I visited the US in September I was told by people close to the administration that Trump had made an offer but Mrs May told him the UK wasn't ready. I was told by people who knew him well and had been appointed to senior positions by him." He declined to name the officials.