This will be the first Labour backbench rebellion – and Starmer’s first U-turn

One of the many puzzling things about the Conservatives’ election campaign is why they have not made stronger attacks on Keir Starmer as a man who will say one thing before an election and do another afterwards.

It has been media interviewers rather than the Tories who have caused Starmer most discomfort on the gap between his platform for the 2020 Labour leadership contest, dubbed “Corbynism without Corbyn”, and the Labour manifesto at this election. Some Starmer allies privately regard this is as his achilles heel.

Perhaps the Tories are addicted to replaying their greatest election hit on tax, even though it doesn’t seem to be shifting the opinion polls this time. Their attacks on Labour sometimes appear contradictory: one minute, Starmer has “no plan”, the next, he has a secret plan to raise lots of taxes.

Starmer’s default response to his policy U-turns since becoming Labour leader is that the economic facts of life have changed, which neatly allows him to introduce Liz Truss into the conversation.

There is one U-turn that Starmer should make as soon as he becomes prime minister. Talking to Labour candidates, I’m struck by how many raise unprompted their distaste for the party leadership’s refusal to abolish the two-child limit on universal credit, introduced in 2017 as part of George Osborne’s austerity drive.

Candidates are already predicting this issue, which restricts child tax credit and universal credit to the first two children in most households, will spark the first backbench rebellion under a Starmer government and, they suspect, his first U-turn as prime minister.

A huge majority might not spare Starmer a revolt. Backbench rebellions are self-regulating – the bigger the majority, the bigger the revolt. Although the vast majority of Labour’s carefully vetted candidates are ultra loyal, backbenchers are more difficult to control than candidates, and newbies like to flex their muscles. There could be twice as many Labour backbenchers than MPs on the “payroll vote” of ministers and aides who have to toe the government line.

A new bloc of Scottish Labour MPs and Anas Sarwar, the party’s leader in Scotland, would be among the first to bang on Starmer’s door. Gordon Brown would doubtless be growling down the phone.

One loyalist candidate told me: “If Keir sticks to the two-child limit, he will have 150 backbenchers on his back.” Another candidate, a close Starmer ally, added: “Everyone wants to see this policy changed. It has got to be at the top of Rachel Reeves’s in-tray.”

The leadership decided against scrapping the cap to send wavering Tory supporters a signal that Labour will not spend money it hasn’t got, or make promises it cannot keep.

Although Starmer has said he is “not immune” to the “powerful” argument for abolishing the limit, the official line is that Labour cannot “wave a magic wand” and would act only when resources allow. Starmer allies play down the idea of an immediate climbdown. One said: “If it’s a choice between the two-child limit and more money for the NHS or Ukraine, what do we do? Sadly, there may be more important priorities.”

But would a Starmer government really stick to this line when another 670,000 children would be affected by the cap by the end of a five-year parliament, pushing the majority (51 per cent) of large families into poverty?

On average, families affected will lose £4,300 a year – 10 per cent of their income. A majority of them have at least one person in work. The number of children in poverty in working households has risen from 2.1 million to 3 million since 2010. This is not about the benefit scroungers the Tories like to demonise as they pledge £12bn of welfare savings.

Labour’s debate echoes a row over Tory cuts to benefits for single parents which the incoming Labour government inherited in 1997. Tony Blair and Harriet Harman, his social security secretary, opted not to reverse them. Forty-seven Labour MPs voted against the government, some 100 abstained, one minister and two private parliamentary secretaries resigned, and another was sacked. Blair’s huge majority won the Commons vote, but it left a bad taste in his party.

Might Starmer prove more flexible? Some Labour insiders think the backbench pressure might force him and Reeves to promise to phase out the two-child limit by the following election.

Starmer might not want headlines about a U-turn. Yet he could argue the money is there in Labour’s manifesto. It contained £7.3bn of revenue-raising measures but only £4.8bn of extra day-to-day spending, leaving a cushion of £2.5bn – more than the £2.1bn of lost revenue from lifting the cap in the 2024-25 financial year, according to the Institute for Fiscal Studies.

It’s surely a matter of when not if a U-turn comes. The cap is indefensible. Even Suella Braverman wants to abolish it. Any Labour government worth its salt would get rid of it.

Far better to do so quickly, give the country a sign that things can only get better and get some credit for it, rather than be dragged kicking and screaming into a grudging U-turn later.