Labour is facing mounting pressure over Britain’s defence spending after a former defence secretary accused the Government of inflating its military investment figures, while a senior national security adviser warned that the country was dangerously underprepared for growing threats.

Sir Ben Wallace has lodged a complaint with the Office for Statistics Regulation (OSR), alleging that the inclusion of billions of pounds in intelligence spending creates a misleading impression of Britain’s progress towards meeting its NATO commitments.

The intervention comes amid wider criticism of the Government’s defence funding plans, with Lord Robertson, the former NATO secretary-general who led Labour’s Strategic Defence Review, warning that Britain’s security was “in peril” and accusing the country’s political leadership of “corrosive complacency”.

Read more related news:

Together, the interventions intensify scrutiny of whether ministers’ spending commitments are translating into the equipment, personnel and long-term investment needed to strengthen Britain’s military capabilities.

Wallace, who served as defence secretary under the Conservatives, argued that headline spending figures risk concealing pressure on the armed forces’ day-to-day budgets.

“As the world gets more unstable and our allies start spending real cash increases in their budgets, Britain seems to be falling behind,” he wrote in a letter to the regulator.

“Telling the men and women of the Armed Forces and the public that they are spending more while in real terms day-to-day funding on our Armed Forces is being cut is an insult to them.”

He added: “It fools no one inside defence, our allies and our enemies.”

The complaint centres on the definition of defence expenditure used by NATO. Wallace argues that spending on security services should not qualify under the alliance’s rules, potentially overstating the resources being directed towards military capabilities.

The OSR confirmed it would consider the concerns raised about the Government’s presentation of defence spending.

Ministers rejected the criticism. A government spokesman told GB News: “The UK is the third highest spender in NATO and we, as with all Allies, calculate defence expenditure in accordance with NATO’s definition, which has not changed.”

The regulator’s consideration of the complaint does not itself establish that the Government’s figures are incorrect.

The dispute over the figures comes as the Government faces separate criticism over delays to the long-term investment plan intended to fund its Strategic Defence Review.

Robertson, a former Labour defence secretary who authored the review, has warned that Britain is failing to respond adequately to the deteriorating security environment.

Speaking in Salisbury, he delivered a stark assessment of the country’s preparedness.

“We are under-prepared. We are under-insured. We are under attack. We are not safe,” he said. “Britain’s national security and safety is in peril.”

He also accused the political leadership of “corrosive complacency”, arguing that ministers had acknowledged the growing risks without taking sufficient action.

“Lip service is paid to the risks, the threats, the bright red signals of danger,” he said, adding that even a promised national conversation about defence had yet to begin.

In a pointed intervention over competing demands on public finances, Robertson warned: “We cannot defend Britain with an ever-expanding welfare budget.”

His criticism carries particular weight because he remains a key government adviser and led the review intended to shape the country’s defence priorities. The Strategic Defence Review was published in June last year, but the accompanying 10-year investment plan has been repeatedly delayed.

Robertson previously told the Financial Times that Sir Keir Starmer was “not willing to make the necessary investment”.

The delay has intensified questions about when the Government will set out how its defence ambitions will be funded and delivered.

Defence minister Luke Pollard rejected the suggestion that ministers were failing to act, saying the Government was “working flat out” to publish the investment plan.

He said additional funding had already been allocated for the current financial year and pointed to continuing announcements of defence contracts.

Ministers argue that the spending and procurement measures will provide Britain’s armed forces with the equipment needed to deter aggression.

But the combination of Wallace’s complaint and Robertson’s warnings puts the Government under pressure on two fronts: whether its spending figures accurately reflect military investment, and whether the resources committed are sufficient to meet the threats identified in its own defence review.

The distinction is significant. Even where expenditure meets NATO’s accounting rules, questions remain over how quickly money reaches frontline capabilities and whether procurement plans provide the armed forces with the equipment they need.

For Labour, the challenge is to demonstrate that its defence commitments amount to more than headline spending targets and strategic declarations.

With the long-term investment plan still awaited and scrutiny of the spending figures increasing, ministers face growing demands to show how Britain will pay for its defence ambitions — and how quickly those ambitions will translate into greater military readiness.