Though seen as a barometer of public anger, the prime minister’s name itself was not on the ballot.

Instead, Britons voted in more than 5,000 local government elections in England, a handful of mayoral contests around London, and votes for the Welsh and Scottish parliaments — devolved legislatures with powers over transport, health and other areas.

Many of those votes were still to be counted Friday, but the partial results pointed to a clear break with the longstanding dominance of Britain’s two establishment parties.

The Conservative Party suffered a chastening defeat in 2024. And the party, now led by Kemi Badenoch, continued to shed votes.

Reform was a big winner, amassing a vast array of council seats in England, while expecting strong showings in Scotland and Wales. The latter looked set to be the first time that Labour would fail to come first in Wales-wide elections in more than 100 years.

Plaid Cyrmu, the left-wing, pro-Welsh independence party, was hoping to win the most seats and lead a coalition government in Wales. Their pro-independence brethren, the Scottish National Party, was likely to do the same north of the border.

The left-wing Green Party hoped for a momentous night, anticipating council gains from Labour in London and other metropolitan areas. Here, younger liberals have become frustrated with Starmer’s efforts to chase the right-wing vote by acting tough on immigration and pursuing a cautious economic agenda.

In sum, the results appear to signal an end for Britain’s postwar two-party system, in which power has changed hands between Labour and the Conservatives, with the Liberal Democrats in a distant third.

Faced with widespread antipathy, those mainstream forces have been hammered by the electorate, with voters increasingly turning to the Greens and Reform, and Plaid and the SNP in Wales and Scotland.

There questions as to how durable support for these left and right insurgents is, however, with both Reform and the Greens facing increasing media scrutiny over their agendas and candidates.

All that said, Britons’ appetite to hand a shellacking to Starmer and the political establishment appears undimmed.

Starmer was already facing enormous pressure over the decision to appoint Peter Mandelson as ambassador to Washington, despite his known links with the late convicted sex offender and financier Jeffrey Epstein. His government has also conducted more than a dozen damaging U-turns, as it failed to capitalize on its 2024 victory and deliver promised help with the cost of living and boosts to public services.

“Keir Starmer is playing existential problems buckaroo at the moment, as he stacks them on the back of his electoral donkey,” said Ben Ansell, a professor of politics and international relations at the University of Oxford. “Everything is happening at once.”

The prime minister seems increasingly likely to face an internal challenge.

High-profile contenders have been rumored to be readying themselves for this moment, including Health Secretary Wes Streeting, former Deputy Prime Minister Angela Rayner and Greater Manchester Mayor Andy Burnham.

If Starmer makes it to the next general election, which can happen no later than May 2029, “that would surprise most political analysts,” Ansell said. “And it would probably surprise most members of the Labour Party at this point, tool.”