UK ‘badly exposed’ and needs 10 years to rebuild its defence, former military chief warns Sir Keir Starmer

The former head of the armed forces has sent a stark warning to Sir Keir Starmer, claiming the UK needs a decade to rebuild its defence even if the prime minister “shows the leadership” to restart investment now.

In a dire assessment about the state of the UK’s military, Lord Jock Stirrup, who was chief of the defence staff during the Tony Blair and Gordon Brown premierships, warned the UK is “badly exposed” and needs “a complete change of mentality” to put it on a war footing.

The former air marshal said he completely agreed with the damning assessment by Labour peer Lord Robertson about UK security being in “peril”, as well as the failures of Sir Keir’s government to tackle the crisis.

Lord Stirrup worked closely with Lord Robertson when the latter was the defence secretary and then Nato’s secretary general.

The crisis comes as the prime minister faces growing criticism over delays to crucial decisions on defence. The long-awaited defence investment plan is still sitting on his desk as the Treasury and Ministry of Defence clash over priorities.

Speaking to The Independent, Lord Stirrup said: “We are badly exposed as a country.”

He went on: “We need to replenish stores, munitions, all the sort of consumables of war, which were already far too low, which, of course, have been reduced significantly because of the number that we have rightly given to Ukraine.

“But secondly, we need, in this country and throughout Western Europe, an agile, innovative and rapidly scalable defence base, defence industrial base. And by defence industrial base, I don’t just mean traditional defence companies.”

He warned that there was no quick fix. He said things are so dire that the UK needs a “graduated” increase in defence spending to rebuild its defence production or simply risk inflation in the sector.

He said: “We have a long, long way to go. We require 10 years of sustained investment in defence to restore our position.”

In a stark warning, he added: “A 10-year process does not mean – as the government often seems to think – that you can leave everything until year eight, nine or 10.”

But the man who oversaw the UK’s involvement in both Afghanistan and Iraq vented his frustration at the lack of leadership from Sir Keir’s government.

Lord Stirrup, who is now a crossbench peer, said: “I see no signs at the moment of the required determination and leadership in the government that’s required to do this because, of course, it requires extremely difficult choices.

Reflecting on Lord Robertson’s warning that welfare spending needs to be switched to defence, he added: “We all understand the pressures on finances. We all understand the pressures on the economy, not least from the rapidly expanding benefits bill, which is a whole different subject by itself.

“But we expect our leaders to lead, and that means when times are tough, making the tough decisions. We didn’t force these people to run the country. They wanted to do it.”

Asked about calls for the UK to cut welfare spending to fund defence, the prime minister’s official spokesman said: “We inherited a situation where defence was being hollowed out at the same time as nearly one in 10 working age people were out of work, including around a million young people

“The government is turning that around by making the investment in defence that our country needs as well as reforming the welfare system to deliver fairness for the taxpayer and support more people into work which is the best way to get the welfare bill down in the long term.”

He added: “We’ve been crystal clear that we want to get the defence investment plan fit for the threats we face.”

The latest intervention comes amid revelations that Rachel Reeves’ Treasury has vetoed spending for a deal for UK peacekeepers to go to Ukraine on top of blocking MoD spending and forcing in-year cuts.

In the last week former Tory defence secretaries Penny Mordaunt, Sir Ben Wallace, Sir Grant Shapps and Labour’s former foreign secretary Jack Straw have all issued warnings about the parlous state of UK defence.

Lord Stirrup has also earlier this year contributed to a hard hitting report for Policy Exchange, where he warned that the UK can no longer rely on its nuclear deterrent for defence without backing it up with other military hardware.

Sir Keir has insisted he is making record investment in UK defence but Lord Stirrup said: “It is easier to make record increases when defence spending was at a record low.”

During PMQs on Wednesday, Sir Keir said he disagrees with Lord Robertson after the former Nato chief accused the government of “corrosive complacency” on defence spending.

Sir Keir said: “Last February, that was seven months after taking office, I took the decision to increase defence spending from 2.3 per cent to 2.6 per cent, paid for by my difficult decision on overseas aid.

“Last June, at the Nato summit, I committed to raising core defence spending to 3.5 per cent. Last November, the budget committed record funding to defence. I reaffirm those commitments now.

“The strategic defence review is a 10-year blueprint for national security. The defence investment plan (Dip) will put that into effect. It will be published as soon as possible.”

During her clash with the prime minister, Tory leader Kemi Badenoch pressed the prime minister on when the Dip will be published, calling for it to come before the end of the parliamentary session.

She said: “Lord Robertson’s criticisms were of the prime minister, and he says Britain’s national security is in peril.

“Our armed forces are at the end of their tether waiting for this government to fund the strategic defence review (SDR).

“There are still two weeks of the parliamentary session left so why won’t the Prime Minister publish the Dip before then?”

Sir Keir did not respond to this directly, instead saying the government is “spending £270 billion over this Parliament, that’s £5bn more this year, with defence funding increasing every year”.