The UK’s potential future prime minister has a significant hill to climb to win back Labour voters who have defected to left and right-wing parties, a poll has found.
Even then, Andy Burnham is expected to reach level pegging with the Reform candidate in the Makerfield by-election, which, if he is successful, could set him on the path to become Britain's next leader.
But the risk the mayor of Manchester took in getting a friendly MP to step aside to trigger the poll for a Westminster seat has been exposed in a Convergent poll of 10,000 voters.
If Mr Burnham is to become an MP for the first time since 2017 – and be the most likely challenger to unseat Keir Starmer as prime minister – he will have to appeal to Labour voters who defected to the left, to the Greens and Liberal Democrats, and those to the right, to Conservatives and Reform UK.
Based on 2026 local election results in Wigan, which includes the Makerfield constituency, he starts 22 points behind Reform’s Robert Kenyon as at last month's local elections Labour took 25 per cent of the votes compared to Reform's 47 per cent. “This is the hill Burnham's campaign now must climb,” Convergent said.
Winning back those in Labour who switched to the left is not enough as this will only get Mr Burnham to 32 per cent. But even winning back Labour voters who defected to Conservatives and Reform, in addition to the left wingers, earns him 37 per cent, matching Reform in that scenario. The latest polling for Makerfield shows Mr Burnham leads Mr Kenyon by three points, within the margin of error.
Winning back voters from both flanks is expected to be the only way Labour can win the next general election, set for 2029, which means success in Makerfield for Mr Burnham will strengthen his leadership credentials.
But he will need to motivate Labour supporters to get out and vote, as the Convergent survey found 38 per cent stayed at home last time, unlike Reform voters.
Left and right losses
The in-depth polling exposed Labour’s losses to both flanks, with 13 per cent defecting to the Greens, 8 per cent to Reform and 6 per cent each to Lib Dems and the Conservatives.
Although Labour is losing more to its progressive flank (19 per cent) than its right flank (14 per cent), the loss to Reform has the most significant implications.
“A direct Labour-to-Reform switcher counts twice over: it takes a vote off Labour's pile and adds one to Reform's, swinging the margin between them by two votes, not one (and the same is true in reverse),” Convergent said.
There’s a chance that a Burnham administration would push the party further leftward than Mr Starmer’s centrist approach but Convergent makes clear “that simply trying to appeal to one type of lost voter isn’t going to work”. Instead, it suggests a single agenda such as reviving Britain’s sluggish economy could appeal to defectors on all sides.
Its findings were reflected too in Labour’s huge loss of support to Reform among its traditional core of trade union members.
New polling by JL Partners showed that it has suffered a 20-point drop since being elected in 2024 with the two parties both on 28 per cent among union members.
