Vote Leave campaigners will be able to claim to have secured the £350 million a week for the NHS

Theresa May will allow Brexiteers to claim that they secured £350 million a week for the NHS days before forcing them to swallow a series of big compromises on Brexit.

The prime minister is expected to set out a multibillion-pound budget boost for the health service, possibly as early as tomorrow, paid for by borrowing of about £10 billion coupled with stealth taxes such as freezing personal allowance thresholds.

Some believe that the government may also cancel planned reductions in corporation tax, although the chancellor, Philip Hammond, has been deeply resistant to the idea.

Mrs May is expected to allow Brexiteers including Boris Johnson to claim the settlement as one of the biggest wins since the referendum.

The foreign secretary has been pressing in public