Jeremy Corbyn was unable to put a figure on how much his party’s proposal to offer 30 hours of childcare a week for all two-year-olds would cost.

In an interview for Radio 4’s Woman’s Hour this morning, the Labour leader was repeatedly asked to explain how much public money would be needed to fund the policy, which would provide care for 1.3 million children in the UK.

He was asked four times by the interviewer, Emma Barnett, how much the policy would cost. A figure only emerged after she quoted back to him an estimate from his shadow education secretary, Angela Rayner: “£2.7 billion and then £4.8 billion, with half a billion to reverse the cuts to the Sure Start scheme”. Mr Corbyn, perhaps relieved to hear some numbers at last, said that sounded “correct”.

Mr Corbyn says that the current provision of childcare is “patchy” and that introducing a universal entitlement for two-year-olds – regardless of their parents’ income – could “transform a child’s life chances and make it much easier for parents to work“.

That may well be the case. But do Labour’s figures add up?

What does the manifesto say?

The last Labour government introduced free childcare hours for parents of young children, but the policy has been eroded over seven years of Tory rule. Today’s commitment is part of Labour’s plan to reform the provision of “early years” support for children and their families, set out in this month’s manifesto.

With all of its manifesto pledges, the party has been at pains to claim all of its proposals would be paid for by tax revenue, rather than government borrowing. The manifesto states quite plainly: “every spending commitment is fully costed. Every source of funding is explained”.

But today’s blunder from Mr Corbyn suggests otherwise.

The manifesto says the party would spend £5.3 billion on “childcare and early years including more money for Sure Start”. But the figures cited in today’s interview – £2.7 billion, £4.8 billion and £0.5 billion – put the total cost of the same package at £8 billion. That’s £2.7 billion more than Labour said it would cost just a fortnight ago in their manifesto.

We asked the Labour Party about this, and they said that the extra money was in fact capital spending. In other words, it would be spent on long term investment (buildings, equipment, training), rather than day-to-day maintenance (like paying staff salaries).

This is a convenient get-out clause that the party have used throughout the manifesto – they call it their Fiscal Credibility Rule. It gives them permission to borrow – and potentially increase government debt – on investment for the long term, so long as they fund day-to-day spending with tax revenue. The extra £2.7 billion for childcare spending comes from the long term investment pot, which means they don’t have to raise taxes to pay for it.

This accounting trick is not unique to Labour (the Tories did it last year) and there are plenty of economists who would back it as a more responsible way of injecting money into the economy to stimulate growth. But it still undermines Labour’s claim to have a fully costed, fully funded manifesto – as we’ve pointed out before.

Will the money they’ve pledged be enough?

So it looks like Labour have just about managed to meet their own measure of fiscal credibility (you’d hope so, given they wrote the rule themselves). But where have they got their childcare figures from in the first place?

The party say their calculations are based on estimates from a 2016 paper by the Joseph Rowntree Foundation (available here), and using this data, they’ve reached the £5.3 billion figure for annual spending on day-to-day childcare.

But the Education Policy Institute published an analysis of the parties’ education plans this month which says Labour’s package would actually cost “closer to around £6.4 billion per year”. That suggests Labour’s figures are £1.1 billion a year short, and could mean a spending gap of £5.5 billion over the parliament. And that doesn’t even include the additional capital funding required for investment.

FactCheck verdict

Labour’s calculations underestimate how much they’d need to spend on childcare by £1.1 billion annually and could create a spending gap of £5.5 billion over the parliament. They’ve pledged an additional £2.7 billion in capital spending on childcare over the parliament – a further example of Labour using creative accounting to give the appearance that their manifesto adds up.