# Will Reform win the next U.K. election

> Liquidity-weighted aggregate at 22% across 4 contracts — refreshed 26 min ago.

URL: https://simplefunctions.dev/odds/ukparty
Updated: 2026-06-26T07:20:49.338Z
Category: politics · Topic: election-2026
Status: active
Closes: 2029-08-31

## Headline

- Probability: 22% (liquidity-weighted across 4 contracts)
- Venue: Kalshi (4 contracts)
- 24h volume: $2

## Bound contracts (4)

| Outcome | Price | 24h | Volume | Venue | Slug |
|---|---|---|---|---|---|
| Labour party | 32¢ | +1pp | $2 | kalshi | /markets/will-labour-win-the-next-uk-election-labour-party-kalshi-kxukparty-29-l |
| Conservative party | 17¢ | +2pp | $0 | kalshi | /markets/will-conservative-win-the-next-uk-election-conserv-kalshi-kxukparty-29-c |
| Green party | 3¢ | ±0 | $0 | kalshi | /markets/will-green-win-the-next-uk-election-green-party-kalshi-kxukparty-29-gre |
| Reform party | 35¢ | +1pp | $0 | kalshi | /markets/will-reform-win-the-next-uk-election-reform-party-kalshi-kxukparty-29-r |

## 30-day trajectory

| Day | Aggregate |
|---|---|
| 2026-05-27 | 25 |
| 2026-06-12 | 14 |
| 2026-06-19 | 9 |
| 2026-06-25 | 17 |

_23 days of price history captured. Each row is the daily mean of intraday 5-min captures._

## What moved the line

- 2026-06-20 · Reform party −3pp 37→34¢ · kalshi
- 2026-06-21 · Reform party +3pp 34→37¢ · kalshi
- 2026-06-22 · Reform party −3pp 37→34¢ · kalshi

## Analysis

This probability represents an 18% chance that Reform will win the next U.K. general election. The current assessment reflects Reform's recent polling performance and organizational capacity relative to established parties like Labour and Conservative. Reform has grown from a fringe party to a notable electoral force, but still faces structural challenges in converting vote share to seat count under the U.K.'s first-past-the-post system. The probability would likely shift based on changes in national polling averages, leadership developments within Reform or competing parties, and how effectively the party can build campaign infrastructure before the election. The next major test will come through by-elections or local council results that provide clearer signals about Reform's ability to translate support into actual victories. Current uncertainty mainly stems from whether Reform's rise represents a durable realignment or a temporary protest vote.

### Key factors

- U.K. national opinion polling shows Reform typically polling between 10-20% of the vote share, but historically first-past-the-post translates this into significantly fewer parliamentary seats than Labour or Conservative parties with similar or lower percentages
- Reform has never won a general election and lacks the ground organization and candidate pipeline of established parties, which typically require years to build
- Changes in Conservative or Labour leadership, or major policy shifts, could redirect protest voters away from Reform or consolidate support around it
- By-election results and local election performance will provide concrete data on whether Reform support transfers from polls to actual ballots in contested seats
- The timing of the next general election (which can occur anytime before January 2030 under current law) affects Reform's preparation time and organizational readiness

## Methodology

Probability is **liquidity-weighted** across all bound Kalshi/Polymarket contracts: Σ(price × volume) ÷ Σ(volume). 30-day trajectory uses the daily mean of intraday 5-min captures. 24h delta = today's mean − yesterday's mean. Movement events are ≥3pp daily moves in the last 7 days.

## How to use this data

- HTML: https://simplefunctions.dev/odds/ukparty
- JSON: https://simplefunctions.dev/api/public/odds?slug=ukparty
- Topic hub: https://simplefunctions.dev/predictions/election-2026

## License

CC-BY-4.0. Attribute "SimpleFunctions" with a link to https://simplefunctions.dev. See https://simplefunctions.dev/legal for terms.