Theresa May pledges to increase defence spending after military chiefs warn UK losing the ability to fight wars

'The armed services are having to seek further very damaging savings in manpower, support and training at a time when the likelihood of combat operations is increasing'

A Tornado GR4 jet: Government defence spending claims were branded an 'accounting deception' (Getty Images)

Theresa May has rushed out a pledge of higher defence spending, after alarmed former military chiefs warned Britain is losing the ability to fight wars.

A letter hand-delivered to Downing Street urged the Prime Minister to recognise a funding crisis risks damaging Britain's standing on the international stage.

“The armed services are having to seek further very damaging savings in manpower, support and training at a time when the likelihood of combat operations is increasing," the letter said.

“These realities of the security situation must be faced,” it added, listing the threats posed by President Putin's “nuclear sabre-rattling” over Crimea and by North Korea.

The signatories – including two former chiefs of defence staff – also accused the Government of an “accounting deception” over claims it meets a Nato target to spend two per cent of GDP on defence.

“Most analysts now agree core defence expenditure for hard military power is well below two per cent,” they wrote.

Now Ms May has announced a Conservative Government will both meet the two per cent target and “increase the defence budget by at least 0.5 per cent above inflation in every year of the new Parliament”.

The pledge matches the promise made by George Osborne in the Budget immediately after the 2015 election - extending it through to 2022.

“As Prime Minister I always have and always will put Britain’s national security first,” Ms May said.

“That is why, if elected on 8 June, I will ensure that the UK continues to spend at least two per cent of GDP on defence and that the budget rises every year.

“Under my leadership, the Conservatives will ensure that the brave men and women of our Armed Forces have the equipment and resources they need to keep our country safe – and that we meet our obligations to the world.”

However, the announcement did not address the damaging accusations that the nation’s war-fighting potential has been put at risk and the figures fiddled.

The Cameron Government started including new items of expenditure, such as military and civil service pensions, contributions to UN peacekeeping missions and much of the MOD's £1.4bn income.

Both the previous Prime Minister and the current one have insisted those changes fall with Nato rules for the target – arguing Britain is one of only five countries to meet it.

The letter praised a 2015 defence review that committed Britain to buying new warships, nuclear-armed submarines, supersonic jets and armoured vehicles.

However, it warned that the Government had failed to pledge enough resources to achieve those aims, with some experts putting the black hole at £20bn.

“Responses by the [Ministry of Defence] to questions about the adequacy of the defence budget raised by respected and informed commentators have been disingenuous, evading the issue by the relentless quoting of irrelevant financial statistics,” the letter said.

Jeremy Corbyn has said “all aspects” of defence would be reviewed if Labour won power, but insisted he would meet the two per cent target.