Hung Parliament 2029: Who Governs?
If no party wins 326 seats in 2029, who would form a government? Coalition maths, confidence-and-supply options and the constitutional rules explained.
The hung parliament baseline
Under current polling (Scenario A), no party reaches 326. Projected seat totals: Labour 180, Reform 120, Conservatives 110, Lib Dems 80, SNP 45, Greens 25, Other 90. Majority threshold: 326 seats. This page analyses every realistic combination for forming a stable government.
Constitutional Framework: How a Hung Parliament Resolves
1. Incumbent First
Under the Cabinet Manual, the incumbent Prime Minister has the right to remain in office and attempt to form a government first, even if they are not the largest party. Starmer could try to form a minority Labour government even if Reform or Conservatives win more seats.
2. King’s Speech Test
Any government must win a vote on the King’s Speech in the House of Commons to demonstrate it can command a majority. If it loses, the PM must resign or request a dissolution. This vote is the real test of whether a government is viable.
3. Coalition vs. C&S
A formal coalition involves junior partners taking Cabinet seats and signing a coalition agreement. Confidence-and-supply (C&S) is looser: a party agrees to support the government on confidence votes and supply (budget) without joining Cabinet. Both deliver stable government.
Option 1: Labour + Lib Dems
The most widely discussed post-2029 scenario. Labour and the Liberal Democrats share broadly similar policy ground on constitutional reform, public services and net zero. The two parties do not have a pre-election pact but both their voter bases expect cooperation in a hung parliament.
| Combination | Seats | Majority? | Assessment |
|---|---|---|---|
| Lab + LD only | 260 | No | Short by 66 — needs further support |
| Lab + LD + SNP | 305 | No | Still 21 short. SNP price = indyref2 |
| Lab + LD + SNP + Green | 330 | Yes | Slim 4-seat majority. Fragile but viable |
| Lab + LD + Green | 285 | No | Short by 41 — minority C&S possible |
| Lab minority only | 180 | No | Must win C&S from others case-by-case |
Lib Dem demands in any deal
- Proportional representation (or a referendum) — their red line since 2010
- Protection of the 0.7% overseas aid target
- Reversal of two-child benefit cap
- Stronger mental health legislation
- Commitments on adult social care funding
Option 2: Reform UK + Conservatives
Politically the most logical right-wing combination. However, the Conservatives under Kemi Badenoch have repeatedly and explicitly ruled out a pact or coalition with Reform UK. The personal animosity between Badenoch and Farage is significant. Despite sharing some policy overlap, a formal deal would be constitutionally unprecedented and politically explosive for both parties.
| Combination | Seats | Majority? | Assessment |
|---|---|---|---|
| Reform + Con only | 230 | No | Short by 96 even combined — impossible on own |
| Reform + Con + DUP etc | 248 | No | DUP ~7 seats adds little. Still 78 short |
| Reform alone (minority) | 120 | No | Cannot govern without massive confidence & supply |
| Con alone (minority) | 110 | No | Even less viable than 2017 without DUP deal |
The Reform problem
Reform UK’s stated ambition is to replace the Conservatives, not work alongside them. A coalition would require Reform to accept Conservative leadership (or vice versa) — politically toxic for both brands. The most likely outcome if Reform is largest party is a second election within 12 months rather than a functioning coalition.
Option 3: Anti-Reform Grand Arrangement
If Reform becomes the largest party (Scenario C: 180 seats), the other parties face pressure to prevent a Reform government. A loose arrangement where Labour, Lib Dems and the SNP all vote against Reform on confidence votes — without formal coalition — is possible. But agreeing on who leads it is the problem.
| Arrangement | Seats | Viable? | Key obstacle |
|---|---|---|---|
| Lab + LD + SNP + Green | 330 | Slim majority | SNP demands indyref2; Green demands climate pledges |
| Lab + Con (grand coalition) | 290 | Short — unstable | Historically unprecedented, destroys both parties’ brands |
| Lab + Con + LD | 365 | Majority | Only works to "stop Reform" — unsustainable for long |
| Labour minority C&S | 180 | Fragile | Requires case-by-case support from 5+ parties each vote |
Most Likely Outcome Under Scenario A
Labour minority + SNP/Green C&S
Labour governs as a minority, seeking support vote-by-vote from the SNP, Greens and Lib Dems. No formal coalition agreement. Works on most legislation but is vulnerable to defeats on budgets and controversial bills. This mirrors how minority governments work in Scotland and Wales. Most likely scenario.
Labour + LibDem formal C&S
Labour agrees a written confidence-and-supply arrangement with the Lib Dems, giving Starmer reliable votes on confidence and the Budget in exchange for specific policy concessions. No Lib Dem ministers in Cabinet. More stable than pure minority government. Possible if Lab is at 180+ and LD at 80+. Second most likely.
Second election within 12 months
If Reform becomes largest party and Labour refuses to serve under Farage, and Reform cannot command a majority, the incumbent PM might request a second election if Parliament cannot pass a King’s Speech. Rare but not impossible — this happened in 1974 when a February election produced a hung parliament and a second October election followed.
SNP leverage in Scotland
With 45+ seats, the SNP would hold significant leverage. Their price for any arrangement would be a Section 30 order for an independence referendum. Starmer has ruled this out. The SNP could abstain rather than back Reform in confidence votes — giving Labour a de facto minority government — without any formal deal.
Confidence-and-Supply: How It Works
A confidence-and-supply agreement commits a party to vote for the government on:
- Votes of confidence — if the government loses one, it must resign or call an election
- Supply (Budget and Finance Bills) — to keep the government funded
On all other votes, the smaller party is free to vote against government policy. This gives the smaller party influence without full accountability. The 2010–2015 coalition was a full coalition; the 2017 Con–DUP arrangement was confidence-and-supply. The DUP extracted £1bn for Northern Ireland in exchange for their votes.
Frequently Asked Questions
Sources & Further Reading
For authoritative detail on hung parliament procedures and coalition negotiations, see the UK Parliament: Hung Parliament guidance. For the 2029 seat context, see our seat calculator and election scenarios.