The UK is “living a lie” about its defence programme, which is unaffordable within current budgets, the former chief of defence staff has said, after a committee of MPs said Britain must raise spending in order to maintain its relationship with the US.

Lord Gen Nick Houghton, who was chief of defence staff until 2016, said the government had to make a tough choice between losing its global standing as a leading defence nation or increasing spending on defence.

His comments echoed the warning of the House of Commons defence committee, which published a report on Tuesday saying that without further investment UK forces would struggle to maintain “interoperability” with the US military, diminishing their usefulness as allies.

The UK defence secretary, Gavin Williamson, has mounted a public campaign for more funds, ahead of the autumn budget, warning Downing Street of the strength of feeling on the Conservative backbenches, though MPs have played down the risk of voting down the budget.

Houghton said David Cameron’s defence programme in 2015 had been ambitious but did not have the required funding to match it, because it had assumed continued growth and that the army could make efficiencies where it could not.

“We’ve got to make a hard choice therefore. Do we increase the defence budget to make it affordable, or diminish our status as a military power?” he told BBC Radio 4’s Today programme.



“We have slightly deluded the public that we have a defence programme which insiders know is unaffordable. We are to some extent living a lie. And we stand at a strategic crossroads and we’ve got to come off the fence one way or another. It might be the UK should cease to be a world military power.”

Houghton said it was “remarkable” that the NHS had recently been promised an increase in annual funding equivalent to more than twice the annual defence budget.

“More funding for health can win you tactical advantage in domestic elections but they don’t enhance Britain’s influence, power and respect in the world if that is the sort of country we want to be,” he said.

However, Houghton sounded a note of caution about the tactics deployed by Williamson, who was reported to have told colleagues he could “make or break” the prime minister.

“It would be a great shame if the future of the defence budget and the armed forces of this country were part of a political game for power and ambition and I hope that is not the case,” he said. “To me the arguments are very strong and stand on their own merits.”

The warning comes ahead of next month’s Nato summit in Brussels where the US president, Donald Trump, is expected to reiterate demands for its European allies to take on a greater share of the burden of collective defence.

In its report, the defence select committee repeated its call for the government to raise defence spending from the Nato minimum of 2% of GDP to 3% – about £60bn a year – saying without additional funding the UK would be unable to maintain its military capacity and capability.

“Diminished capacity reduces the UK’s usefulness to the US and our influence within Nato. The government must not allow this to happen,” it said.

The committee said that the US defence secretary, James Mattis, had estimated that the UK benefited to the tune of £3bn a year from its defence relationship with the US.

“This implies that both the UK armed forces and HM Treasury benefit from our close relationship with the US,” it said.

“However, that will continue to be true only while the UK military retains both the capacity and capability to maintain interoperability with the US military and to relieve US burdens. For this to be the case the UK armed forces must be funded appropriately.”

A spokesman for the Ministry of Defence said: “The UK maintains the biggest defence budget in Europe. We have been clear we will continue to exceed Nato’s 2% spending target.

“The defence secretary launched the Modernising Defence Programme to strengthen our armed forces in the face of intensifying threats.”