Theresa May has agreed to pour an additional £384 million per week into the NHS after Brexit – exceeding the amount mooted by the official Leave campaign and effectively locking the UK into leaving the EU.

The boost for the health service, which the Prime Minister will formally set out in a speech on Monday, is intended to mark the 70th anniversary of its creation, partly by drawing on the “Brexit dividend” that will arise from the country ceasing payments to the EU.

Mrs May said on Sunday the funding would also come from the nation "contributing a bit more" as she signalled taxes are likely to rise to meet the pledge.

Writing in The Sunday Telegraph, Jeremy Hunt, the Health Secretary, who campaigned for Remain during the 2016 referendum, says the Brexiteer pledge of extra funding for the NHS “can now unite us all”.

In a heavily criticised slogan, the Leave campaign had said the UK sent £350 million per week to the EU in cash terms, which could be spent on the NHS instead.

Mrs May’s decision to fund the increase partly from the "Brexit dividend" signals an insistence that the UK will leave the EU next year, and is likely to frustrate pro-Remain MPs and peers pushing for the country to stay within the bloc or keep the closest possible ties.