“Every spending commitment is fully costed. Every source of funding is explained.”

That was the claim from John McDonnell in the foreword to Labour’s manifesto “costing document”, published last week.

But within days, the document was out of date. On Saturday, the party announced an extra £58bn for “WASPI women” who lost out after the government changed the pension arrangements for millions born in the 1950s.

And it’s not the only gap in Labour’s plans. FactCheck takes a look.

Millions of women to pension compensation

In 2011, the Conservative-led coalition government decided to bring forward planned rises to the state pension age for women to bring the retirement age in line with men.

Campaigners, including the “WASPI” (Women Against State Pension Inequality) group, say they were not given enough time to prepare for the change and have lost out financially as a result.

Some 3.7m women born in the 1950s are thought to be affected.

Labour’s manifesto said a Labour government “will work with these women to design a system of recompense for the losses and insecurity they have suffered.”

But just two days later, Labour seemed to accelerate their plans, promising payouts to affected women worth £15,380 on average (with some expected to get as much as £31,300).

The party say they expect to spend £58bn on compensation in total over five years.

This money was not included in the Labour manifesto costing document, which had already promised £83 bn more than existing government plans in “day-to-day” spending by 2023-24.

They expect an £83-bn tax haul over the same period, which would balance the books.

But this new announcement will increase Labour’s planned extra spending significantly. The party has yet to say how this will be funded.

We asked Labour whether the announcement was costed in their manifesto. A spokesperson told FactCheck: “Redressing the historic wrong of women having their pensions stolen by the Conservatives and Liberal Democrats is the right thing to do and we will treat it in the same way as a government losing a legal case and needing to pay one-off compensation.”

How much would nationalisation cost?

And Labour’s spending won’t end there. The party says it will nationalise the rail, mail, water and energy sectors — as well as broadband, which will be provided free to customers.

But as we reported earlier this month, there’s a big question that remains unanswered: Labour can’t tell us how much they will spend to buy these companies.

A party spokesperson told us: “In line with UK legal precedent, Parliament will decide the level of compensation and there will be a process of negotiation with companies. The starting point for these negotiations will be a fair assessment of the true value of the companies (including the many that aren’t listed and therefore don’t have a market value) and of what is a fair level of compensation for the taxpayer.”

They also said a Labour government “will compensate at a fair rate, not the wildly exaggerated rates floated by certain interested parties”.

But we don’t know what that rate will be. Without that vital piece of the puzzle, we can’t say how much Labour’s nationalisation plans would cost.

The 32-hour work week

Labour’s manifesto says: “Within a decade we will reduce average full-time weekly working hours to 32 across the economy, with no loss of pay, funded by productivity increases.”

But the party’s costing document says it does not account for the effect of this policy on the public finances “because it is a target for year ten of a Labour government”.

Yet Labour have elaborated on other decade-long policies in the document, including “£250bn over ten years for our Green Transformation Fund”.

And more importantly, a move towards a 32-hour week would not happen overnight. It’s fair to expect that the effects of workers and employers moving towards this target would start to materialise before “year ten” of a Labour government.

FactCheck verdict

John McDonnell said that Labour’s manifesto was fully costed and with “every source of funding” explained.

But in the days since it was published, they have announced an extra £58bn of spending on compensation for women who lost out from pension changes, and we don’t know where this money would come from.

And we don’t have all the necessary information to work out how much two other flagship Labour policies (nationalisation and the 32-hour working week target) will cost.