The surge in Green Party support in the Gorton by-election re-enforces the nationwide pressure the party is putting on Labour as it reshuffles the political position of the left in Westminster. Whereas the Greens took only an eighth of the national vote of the three left of centre parties in 2024, in current polls it is taking almost one-third of the combined Labour, Green and Liberal Democrat support.
All of the 56 seats that Electoral Calculus predicts the Greens can win nationally would come from Labour. This would leave Labour, with 79 predicted seats, only 23 seats ahead of the Greens. A small increase in Green support and a fall in Labour support would put the Green Party ahead of Labour in parliamentary strength.
The reshuffle of seats between the Greens and Labour does nothing to strengthen the left overall. At present Labour and the Greens are predicted to gain only 135 MPs if an election were held today. If the Liberal Democrats became a partner, the three parties of the left together would have only 200 MPs, far short of what would be needed to form a minority government let alone a majority government.
The Greens have adopted left-wing Labour policies without the disadvantage of wearing the fiscal straightjacket that the government sports. This makes it difficult for Labour to prevent supporters disillusioned with its record in government from defecting to a party promising policies to appeal to Labour's soft and hard left voters.
Labour has been trying to win back support from the Greens by arguing that it is the only party that could prevent Nigel Farage and Reform UK from taking control of British government. The Electoral Calculus national prediction is that Reform is only 18 seats away from winning an absolute majority and has a one in four chance of gaining an absolute parliamentary majority
In the Gorton by-election the Greens claimed it was the best party to keep Reform out of office. It won with its support up to 41pc, 28pc higher than at the general election. It was helped in doing so by promoting its support for Gaza in a constituency with a large Muslim population. The vote of Reform's anti-immigrant candidate went up by 15pc to finish second. Labour lost half its vote, finishing third in a seat it had held for more than ninety years. It showed that Labour can't rely on anti-Reform rhetoric to stop many of its supporters defecting to the left and to the right.
Nationally, Conservative support in the polls has stopped falling and the Greens' gains from Labour are putting the Tories close to replacing Labour as second in the polls and in seats won.
There is no sign at present of a reshuffle of votes on the right. Reform UK remains first in the polls, ten percent above the Conservatives. Reform's predicted total of 308 seats shows that the electorate sees it as the party to stop Labour from keeping control of government.
Prof Richard Rose's, Britain's senior psephologist, is the author of The Disruption of the British Party System: a Guide to the Next Election, which Manchester University Press will publish in June.