Makerfield by-election: Crunching the numbers - why Burnham's win is so significant

The result lived up to the hype. An unprecedented contest ended in a seismic result, as Andy Burnham was announced as the new Labour MP for Makerfield with 55% of the vote, more than 20 points ahead of his defeated Reform opponent Robert Kenyon.

A seat whose wards swung hard to Reform last month in local elections has now swung back just as hard to Labour.

With Labour trailing Reform by double digits in national polls, the Greater Manchester Mayor achieved a bigger win over Reform, on a higher turnout, than his predecessor Josh Simons managed in 2024.

Labour won 54.8%, up 9.6% on 2024; Reform won 34.5%, up 2.7%, meaning a 3.4 point swing from Reform to Labour. Burnham returns to Westminster with a majority of 9,231 (20.3%).

This was, of course, no normal by-election.

Burnham is widely believed to have prime ministerial ambitions; his main opponents in the seat, Reform UK, sought to slay a local political giant.

Makerfield's voters responded strongly to these extraordinary circumstances by turning out in exceptional numbers.

Turnout in the seat was 58.7%, up on 52.5% in the 2024 general election, the first time since the SDP's gain of Greenwich in 1987 that a by-election has seen higher turnout than the preceding general election.

The 6.2% rise in turnout on the general election is the third highest in post-war electoral history - only Torrington (11.4%, 1958) and Montgomeryshire (8.4%, 1962) were bigger.

Burnham's win involved a second rare achievement - he achieved a by-election swing to the governing party.

The last time a governing party gained ground in a by-election was in Hartlepool in 2021 at the peak of Boris Johnson's "vaccine bounce", while the last time Labour saw a vote increase while in government was in Beckenham in 1997, at the height of Tony Blair's post-landslide electoral honeymoon.

Although they were narrowly defeated, this was on many metrics a strong performance for Reform. The 15,696 votes the party won in Makerfield is the party's best ever vote total, surpassing the 12,645 votes the party won when taking Runcorn and Helsby from Labour last May by a margin of six votes. Reform's 34.5% vote share this time is second only to the 38.7% won in Runcorn and Helsby.

One reason Reform fell short despite a record vote total was the exceptional squeeze on support for the three other national parties in England's current five party system. The Greens (0.7%), the Liberal Democrats (0.4%) and the Conservatives (2.2%) all lost their deposits, and all saw their vote shares fall sharply on the 2024 general election.

The Liberal Democrats' 0.4% of the vote is the lowest vote share for a major party in any by-election, surpassing the party's 0.9% in Rochester and Strood. The Conservatives' 2.2% was their second-lowest ever by-election vote share, beaten only by the February Gorton and Denton contest.

This by-election was the first contested by the Restore Britain party, founded by former Reform UK MP Rupert Lowe earlier this year. Restore candidate Rebecca Shepherd won 6.8%, an impressive showing for a first by-election contest by a new party.

The past electoral strength of the far-right British National Party, which won 7.4% in Makerfield in 2010, may help explain why there was a substantial constituency here for Restore, whose signature policy is the mass deportation of immigrants.

Reform will no doubt grumble about Restore as spoilers, but even winning every single Restore vote would have left Reform well short here.

This by-election forms part of an emerging trend of anti-Reform tactical voting in by-elections.

In the Senedd by-election in Caerphilly, the anti-Reform vote coalesced behind Plaid Cymru, in Gorton and Denton they backed the Greens, and here they rallied behind Burnham's Labour.

Labour and Reform will clash at the polls again soon, as Burnham's win this week now triggers another Manchester by-election, this time to pick Burnham's replacement as Greater Manchester mayor, which must by law take place by 6 August.

This contest will be, in electorate terms, by far the largest by-election Britain has ever seen, and will either form the backdrop for an ongoing leadership struggle at the top of the Labour Party or provide a big early test for any new leader.

(c) Sky News 2026: Makerfield by-election: Crunching the numbers - why Burnham's win is so significant