Keir Starmer accused Kemi Badenoch of “a desperate search for relevance” as the pair clashed over the government’s plans to boost defence spending.

The prime minister delivered the brutal slapdown after the Tory leader highlighted apparent discrepancies between him and defence secretary John Healey.

Starmer claimed yesterday that the defence budget will go up by ”£13.4 billion year-on-year” from 2027.

But on TV this morning, Healey said this morning that after inflation is taken into account, the real terms increase was actually only around £6bn.

At PMQs, Badenoch asked Starmer: “Over the weekend I suggested to the prime minister that he cut the aid budget and I am pleased that he accepted my advice. It’s the fastest response I’ve ever had from the prime minister.

“However, he announced £13.4 billion of additional defence spending yesterday. This morning, his defence secretary said the uplift is only £6bn. Which is the correct figure.”

The prime minister replied: “I’m going to have to let the leader of the opposition down gently. She didn’t feature in my thinking at all. I was so busy over the weekend I didn’t even see her proposal. 

“She’s appointed herself, I think, the saviour of western civilisation. It’s a desperate search for relevance.

“If you take the numbers for this financial year, and then the numbers for financial year 27/28, that’s a £13.4bn increase - the largest sustained increase in defence spending since the Cold War.”

Badenoch told the PM his answer “wasn’t very clear” and asked him: “How is it that the defence secretary says £6bn and he says £13.4bn? The [Institute for Fiscal Studies] said today that the government is playing silly games with numbers. How does he find this difference in numbers?”

But Starmer hit back: “We went through this two weeks ago, of going over the same question again and again. 

“If you take the financial year this year and then you take the financial year for 2027/28, the difference between the two is £13.4bn. That’s the same answer. If you ask again, I’ll give the same answer again.”

Badenoch then told him: “Someone needs to tell the prime minister that being patronising is not a substitute for answering questions.”