Why the rise in defence spending doesn't add up

At Prime Minister's Questions, Keir Starmer repeated his claim that the increase in defence spending he announced on Tuesday will amount to £13.4bn a year.

- JOHN RENTOUL

He was asked by Kemi Badenoch to explain how he arrived at that figure when the independent Institute for Fiscal Studies (IFS) says the increase is £6bn a year in real terms – a figure John Healey, the defence secretary, has accepted.

As Badenoch pointed out, the IFS has said the government is playing “silly games” with numbers.

Starmer said: “If you take the numbers for this financial year and the numbers for the ’27-28 financial year, there is a £13.4bn increase.” He offered no further information, and neither did his spokesperson afterwards, so we – and the IFS – cannot be sure how he arrived at this figure.

What are the possible explanations?