Who’s afraid of the Green party? Within Labour, the answer varies depending on which member of the shadow cabinet you speak to. Some laugh off the idea that the Greens present an electoral threat from the left, because of the two-party system. As one party veteran puts it: ‘Labour has two opponents. In England, it’s the Tories. In Scotland, it’s the SNP. It’s that simple.’ The prevailing view among many of Keir Starmer’s disciples is that left-wing voters – Green or not – will be so desperate to oust the Tories that they will vote for Labour no matter what.

Concern about a Green threat tends to be code for saying Starmer is not radical or left-wing enough

On the other side of the shadow cabinet table are those who think there is a risk in the Labour party looking Tory-lite. ‘I do worry about the Greens,’ says one shadow minister. ‘There’s a chance that voters go there instead.’ A recent YouGov MRP poll in the Telegraph suggests the Greens pose a threat to shadow culture secretary Thangam Debbonaire. It projected that the Greens are just four points behind Labour in the seat she is contesting, Bristol Central. ‘There’s a reason she’s not been sent on the morning rounds to defend Starmer’s position on Gaza,’ says one Labour figure.

The internal debate also provides a helpful way of finding out how MPs feel about the current direction of the party. Concern about a threat from the Greens tends to be code for saying Starmer is not radical or left-wing enough.

Nowhere is the quandary more apparent than the confusion over the pledge Labour made three years ago to borrow £28 billion a year to reach clean power by 2030. The scheme makes up a large part of Labour’s economic strategy, yet rising borrowing costs mean it has already been scaled back once. In the words of one party figure, the spending commitment has become an ‘albatross around our neck’. The Tories plan to run an aggressive campaign arguing that the pledge will inevitably lead to tax rises. For some in the shadow cabinet, even hearing the figure repeated is a source of frustration. ‘It is very Labour to talk about how much we are going to spend rather than what it will actually do,’ says one shadow minister. Darren Jones, shadow chancellor Rachel Reeves’s deputy, says the pledge has been rendered out of date by rising borrowing costs and the level of private sector capital.

The party is in a no man’s land on the policy as speculation runs on and the £28 billion figure is mentioned sporadically by Starmer. There has consequently been some briefing against his chief of staff, Sue Gray, who is accused of being sympathetic to the pledge to avoid an embarrassing U-turn. But some shadow cabinet members see this as a classic example of the Labour old boys’ club blaming the woman rather than the man she works for. ‘Sue is a true sister,’ says one supportive colleague.

The general expectation in both the Labour party and Conservative HQ is that Starmer and Reeves will junk the headline figure after the Spring Budget, blaming the Tories for using up all the fiscal headroom.

What about the risk of scrapping it? As a Labour strategist once put it: ‘When people ask me how we solve the Green party problem – well, that’s when you get Ed Miliband and his green ukulele to turn out.’ But ditching the £28 billion price tag would be seen as Miliband losing the argument. There are already rumours swirling that Jeremy Corbyn is planning to launch a new party aimed at winning over voters angered by Starmer’s stance on Gaza and Labour’s backtracking on green issues.

While the Greens won just 2.7 per cent of the vote at the last general election (double their vote share in 2017), the ‘green universe’ of voters is much broader. Many voters are environmentalists to a degree. Research for The Spectator by Focaldata estimates that seven million voters are ‘green-curious’. Of this group, 43 per cent would vote Labour; 20 per cent for the Lib Dems; just 15 per cent for the Greens and 8 per cent for the Tories at the next election.

These green-curious voters fall into five categories. First, the ‘Radical Red’ Greens, who are Labour-loyal, environmentally conscious activists who tend to be graduates. They rally behind policies such as the introduction of a four-day week and prioritise climate change along with health and housing.

Then there are the ‘Green Populists’, caught between the Green party and Labour. They believe that Labour represents the working class but think the Greens better reflect their interests on immigration, welfare, job security and climate change. They are the most likely of the five groups to support the Green party in the next election.

Next come the ‘Green Moderates’. They dislike Greta-style jeremiads and tend to be more pragmatic. Among this group, support for Labour is rising. The idea of a Green New Deal type of programme – popular with big business – fits with their eco-activism.

The smallest faction is the ‘Evergreen Optimists’. These voters regard themselves as positive and open-minded. They believe in the political system and prioritise policies over party victories. This group is likely to vote Green.

Finally, there are the ‘Urban Random’ Greens, a cohort of young Londoners who are notably a little more right-wing than the other groups. They are sceptical of some green principles including net-zero targets and ultra low emission zones. They favour the Lib Dems to the Green party on climate issues. More than half of those in this group who voted Green last time say they won’t at the next election in a sign that the party’s policies have become too radical.

Polling suggests Labour, for now, holds sway with many ‘green-curious’ voters. It’s why many in the party think it is better to risk a bust-up with them than damage the party’s economic credentials. Yet Labour’s internal fight over its green commitments goes beyond concerns about an immediate electoral risk. It is about what Starmer and his party ought to stand for.