Next UK Prime Minister 2026

End of 2026 — UK PM question

Polymarket's Categorical book on who's UK PM at the end of 2026 ($453K 24h volume) is the heaviest-traded prediction-market view on Keir Starmer's tenure. Kalshi lists the same field as the longer-horizon KXNEXTUKPM-30 (durable through 2030). Three Manifold markets add finer-grained reads on Starmer's exit probability and timing.

The book is open. Starmer's Labour government is the incumbent; the Polymarket and Kalshi Categorical fields list Lucy Powell, Wes Streeting, Angela Rayner, Yvette Cooper, Andy Burnham, Shabana Mahmood, Rachel Reeves on the Labour side; Kemi Badenoch and Nigel Farage on the Conservative/Reform side; and longer-tail names across both books.

Workspace anchor: Polymarket — Next UK Prime Minister in 2026? · Kalshi — KXNEXTUKPM-30.

Copy this workspace to your account to track through the year.

Anchor cross-exchange — Categorical books

Polymarket and Kalshi both list the UK PM question as a Categorical field. Pies show every named candidate; the cross-exchange spread on Labour-bloc successors vs. Reform UK is the read.

Manifold context — Starmer-stays-or-goes

Two Manifold markets price the Starmer-exit question directly: a Categorical on the date Starmer is replaced, and a Single on whether he ceases to be PM in 2026 at all.

Adjacent context — broader leader-exit markets

Polymarket's "next leader out of power before 2027 (no Orban)" and Kalshi's G7-leader-out field place the UK PM question alongside the broader 2026 incumbent-leader-attrition book; useful for triangulating Starmer-stays-or-goes against the global incumbent-exit base rate.

What to watch

• Cross-exchange Categorical spread. Polymarket and Kalshi list the same set of candidate names but at very different liquidity—Polymarket pricing dominates on weight but Kalshi's book is North-American-resident, so the spread on any single name is a market-structure read as much as a political one.
• Starmer-stays-or-goes is the binary underneath the Categorical. Manifold's two ACX-2026 markets and the Starmer-out-as-PM market price the exit probability directly; when the Polymarket Categorical's "none of the named candidates" residual rises, that's the implied probability Starmer survives the year.
• Trigger events. A vote-of-no-confidence, a major by-election loss, a Cabinet resignation, or a sudden Labour-leadership challenge would each move the Categorical sharply. The Polymarket Multi resolves December 31, 2026.
• Long horizon view. Kalshi's KXNEXTUKPM-30 runs to 2030, so its name field is wider and includes successor-of-successor names; useful as backdrop, not a print-day signal.