LONDON — U.K. Prime Minister Keir Starmer fought to maintain his grip on power Tuesday as the revolt inside the Labour Party widened following devastating local election losses, with junior ministers quitting and nearly 90 lawmakers demanding he resign or map out his exit.

Starmer told his weekly Cabinet meeting that he took responsibility for last week’s election drubbing but would not step aside. “The country expects us to get on with governing,” he said, adding that the past 48 hours of instability “has a real economic cost for our country and for families.” That cost surfaced immediately in financial markets: the interest rate on British government bonds rose more than those of comparable nations, a sign that investors were growing more cautious about holding U.K. debt.

The first ministerial resignations came Tuesday. Miatta Fahnbulleh, the minister of housing, communities and local government, quit and urged Starmer “to do the right thing for the country.” She was quickly followed by Jess Phillips, the safeguarding minister and a prominent Labour figure, who in her resignation letter described Starmer as “a good man fundamentally” but said she was “not sure we are grasping this rare opportunity with the gusto that’s needed.” Phillips wrote that she “cannot keep waiting around for a crisis to push for faster progress.”

The rebellion has split Labour’s parliamentary ranks. More than 100 MPs signed a letter declaring it was “no time for a leadership contest,” while about 90 others publicly called on the prime minister to resign or at least set a timetable for his departure. That number is not yet enough to trigger a leadership election under Labour rules; a candidate would need the public backing of at least 81 lawmakers — a fifth of the parliamentary party — to force a contest, and no challenger has yet come forward.

Speculation centered on Health Secretary Wes Streeting, who is widely seen as a potential successor. Streeting dodged shouted questions from reporters outside Downing Street and is expected to meet Starmer early Wednesday morning. The maneuvering drew comparisons to the 2022 mass resignations from Boris Johnson’s government that forced the then‑prime minister’s exit, though no Cabinet minister has yet quit Starmer’s government.

Several senior ministers voiced support for Starmer after the Cabinet meeting. Works and Pensions Secretary Pat McFadden said nobody publicly challenged the prime minister, while Business Secretary Peter Kyle described him as showing “really steadfast leadership.” Deputy leader David Lammy warned Labour lawmakers that the party’s “navel‑gazing” would only benefit the populist right and the Reform UK leader Nigel Farage. “He has my full support,” Lammy said.

Beyond Streeting, other names circulating as possible successors include Angela Rayner, the former deputy prime minister who resigned last year over an unpaid tax bill, and Andy Burnham, the Greater Manchester mayor who is widely popular but not currently in Parliament. Burnham would need a seat, likely by having a close ally vacate one in northwest England, although such a maneuver has been blocked before and could be risky given last week’s electoral results.

Starmer’s standing has weakened amid a series of policy missteps, a sluggish economy, and lingering questions over his appointment of Peter Mandelson as ambassador to Washington despite Mandelson’s ties to the convicted sex offender Jeffrey Epstein. The local election results saw Labour squeezed from both the right and the left, losing votes to the anti‑immigrant Reform UK, the Green Party, and nationalist parties in Scotland and Wales — a reflection, the Associated Press reported, of the increasing fragmentation of British politics.