London, May 14 -- British MP Wes Streeting has resigned as health secretary, dramatically escalating the internal political crisis facing PM Keir Starmer, and further fuelling speculation that Streeting could launch a leadership challenge for the top job in the Labour Party.

In a sharply worded resignation letter, Streeting bluntly said that he had "lost confidence" in Starmer's leadership and could no longer remain in government.

"It would be dishonourable and unprincipled to continue to serve," he wrote in his letter, according to BBC.

Streeting described last week's disastrous election results as "unprecedented," both because of the scale of Labour's defeat and the political consequences now unfolding inside the party.

He further cau...