Starmer Resigns on Brexit's 10th Anniversary as UK Braces for Seventh PM in a Decade

Seven prime ministers in ten years

Keir Starmer announced his resignation as UK prime minister on Monday, June 23 — the exact 10th anniversary of the Brexit referendum — capping a turbulent decade that has cycled through six leaders and left the economy measurably smaller than it would otherwise have beennbcnews +1. Andy Burnham, the former mayor of Greater Manchester and the runaway favourite to succeed Starmer, would become the seventh prime minister in a decade if selected by the Labour Party in the coming weeksfortune +1. The timing was grimly symbolic: in the 35 years before the 2016 vote, Britain had just five prime ministersfortune.

Starmer, who won a historic landslide in 2024, saw his standing eroded by a series of U-turns, a local-election drubbing and the economic shock of spiking energy prices following the U.S.-Israel war with Irannbcnews. His departure also forced the postponement of a July 22 EU-UK summit that had been set to finalise an agrifood agreement, an emissions trading deal and a youth mobility scheme — a key pillar of his promised post-Brexit "reset"politico.

The economic bill a decade in the making

A National Bureau of Economic Research working paper found that over the past decade, Brexit reduced UK GDP by 6% to 8%, with investment down 12%–13%, employment off 3%–4% and productivity declining a similar amountfortune. Economists at Oxford Economics describe Brexit as "a constant drag on the economy" that continues to reduce output compared with what it would otherwise becnn.

On at least one of the Leave campaign's central promises — control of immigration — Brexit delivered the opposite result. Net migration averaged 550,000 a year between 2021 and 2024, roughly double the rate in the 2010s, peaking at nearly 950,000 in 2023cnn. Six in ten Britons now think Brexit was a mistake, according to a YouGov poll published earlier this monthcnn.

What Burnham inherits — and what remains out of reach

Burnham enters with high personal approval ratings and a record of economic growth in Greater Manchester, but analysts warn he faces the same structural bind as his predecessors: how to grow the economy without raising taxes or unnerving bond marketsnbcnews. A demographic squeeze compounds the problem — the Office for National Statistics projects that deaths will outpace births in the UK from mid-2026, making net migration the sole driver of population growth even as immigration levels remain politically contentiousfortune.

Rejoining the EU is not on the table. Business groups and most politicians across parties argue that returning to the bloc would generate yet another bout of destabilising uncertainty for companies still adapting to post-Brexit trade rulescnn. What Burnham's supporters hope instead is that he can bring his cross-party Manchester formula — pragmatic public investment, closer ties with European partners — to a country that, as one constitutional lawyer put it, has seen Brexit make it "almost ungovernable"nbcnews +1.