Wes Streeting has resigned as Britain’s health secretary, intensifying pressure on Prime Minister Keir Starmer amid growing unrest inside the Labour Party.

In a resignation letter released on Thursday, Streeting said he had “lost confidence” in Starmer’s leadership and argued it would be “dishonourable and unprincipled” to remain in government.

The resignation follows days of speculation over whether Streeting would launch a formal challenge for Labour’s leadership.

Although he did not officially announce a campaign, he called for a broader debate about the party’s future and “what comes next”.

Streeting criticised Labour’s recent election performance, warning that “nationalists” were gaining power across the United Kingdom and claiming progressive voters were “losing faith” in the party.

“Where we need vision, we have a vacuum. Where we need direction, we have drift,” he wrote.

Nearly 90 Labour MPs have publicly urged Starmer to step down after heavy losses in local elections in England and parliamentary contests in Scotland and Wales.

Streeting is the first senior government minister to resign since the internal revolt began.

Downing Street has continued to insist Starmer will remain leader, with the prime minister warning earlier this week that replacing him would return Britain to political “chaos”.