Boris Johnson suffered a major blow to his authority as British prime minister as a senior member of his cabinet quit with a ferocious attack on his leadership.

Amber Rudd resigned as work and pensions secretary and left Johnson’s ruling Conservative party, accusing him of “political vandalism” and alleging he was not trying hard enough to secure a Brexit deal with the European Union.

In a furious resignation letter, Rudd said she could not accept Johnson’s decision to expel 21 Tory members of parliament
from the party over their refusal to follow his orders in a vote on his Brexit strategy last week.

“This short sighted culling of my colleagues has stripped the party of broad minded and dedicated Conservative MPs,” she wrote to Johnson.

“I cannot support this act of political vandalism.”

 Rudd’s resignation plunges Johnson’s six-week-old administration deeper into turmoil after a dramatic and disastrous week.