Theresa May and her husband, Philip, arriving at church in Maidenhead yesterday STEVE PARSONS/PA

Theresa May is facing a black hole in her £25 billion plan to fund the NHS after ministers were unable to agree all of the sources of revenue before the announcement.

The government has yet to confirm a plan for finding up to £11 billion of the money promised yesterday, with the prime minister making clear that tax rises are on the way in the autumn budget.

She told LBC Radio that “we as a country will contribute a bit more” while government officials told The Times: “We’re going to have to have a conversation about tax.”

Mrs May announced yesterday that by 2023, the budget for NHS England will rise by £20 billion a year compared with today’s figure. On top of this, the…