Polymarket odds for UK PM Keir Starmer's 2026 exit rise amid Mandelson-Epstein scandal

Crypto-powered prediction platform Polymarket has seen notable trading volume tied to the political future of UK Prime Minister Keir Starmer, as users wager on whether — and when — he could leave office.

More than $2 million has been traded on a Polymarket contract asking whether Starmer will exit his post by specific deadlines in 2026, according to data from the platform. As of Friday, traders were assigning a roughly 41% probability that Starmer is out by the end of June and roughly 65% by year-end — up from 22% and 51%, respectively, over the past two days — though the figures fluctuate in real time.

The market has attracted increased attention as political pressure on Starmer’s leadership has intensified amid controversy over the government’s handling of documents linked to former Labour heavyweight Peter Mandelson — whose past relationship with convicted sex offender Jeffrey Epstein has come under renewed scrutiny — and over Starmer’s earlier decision to appoint him as UK ambassador to the United States — a move later reversed. Starmer has faced criticism from both opposition parties and members of his own Labour Party over the episode, which has exposed internal divisions and raised questions about his authority, according to the BBC.

Polymarket allows users to trade yes-or-no outcomes on real-world events using cryptocurrency, with prices moving in response to changes in information, sentiment, and liquidity. The contracts resolve based on verifiable public outcomes and are designed to aggregate crowdsourced expectations rather than predict results.

"On Polymarket, traders are currently pricing Keir Starmer as more likely than not to leave office by late 2026," said Tim Meggs, co-founder and CEO of LO:TECH, speaking at the Digital Assets Forum in London. He added that such markets tend to reflect how participants react to uncertainty, rather than serving as a judgment on political leadership.

Otto Jacobsson, CEO of communications firm YAP Global, stated that prediction markets are increasingly used to hedge political risk. "It’s a crowdsourced approach to assessing probabilities," he said, noting that early usage can resemble gambling but also signals a broader shift in how uncertainty is priced.

Regulatory tussle

Polymarket has previously drawn heavy trading volumes around high-profile political and geopolitical events, including the U.S. presidential election, where its odds closely tracked eventual outcomes, as well as markets tied to international conflicts in Ukraine and leadership changes in Venezuela.

While users bet on Starmer’s future, an evolving regulatory backdrop is unfolding across jurisdictions.

In the U.S., the Commodity Futures Trading Commission withdrew a Biden-era proposal that would have restricted political event contracts, even as state regulators continue to challenge prediction market platforms over jurisdiction and compliance. Companies, including Coinbase, Kalshi, and Polymarket, have faced scrutiny from state authorities over sports and political contracts as prediction markets increase in demand.