Reducing the size of the army “beggars belief” and the lack of “properly functioning” reserve forces is a “national embarrassment”, a former head of the UK armed forces has said.

Lord Nick Houghton, who was chief of the defence staff between 2013 and 2016, criticised the decision to cut regular troop numbers during an appearance before the House of Commons Defence Committee on Tuesday.

He said: “It beggars belief to me that we have a reduced size of army.

“We have witnessed the first real formalised warfare above the threshold of war in Ukraine and Russia and within weeks both sides have sort of run out of troops.

“They have mobilised their nations, they have had to call on reserves and yet we as a nation have no strategic methodology for mobilising the reserves. We don’t have a properly functioning reserve. To me it’s a national embarrassment but they don’t appear to want to do anything about it.”

The size of the British Army has been a source of political argument in recent months, with Labour calling for a halt to the cuts announced in the last defence command paper, published in 2021.

Afghanistan war commemorations
Lord Houghton with then-prime minister David Cameron. The former chief of the defence staff said he warned Mr Cameron about the increasing threat from Russia (Toby Melville/PA)

In the past decade, the number of regular soldiers has fallen from 97,000 to 76,000 and is set to fall to 73,000.

Lord Houghton, who spent 40 years in the army and served in Northern Ireland and Iraq, said the UK’s military capability had not been “eroded to the point where we should worry”, but acknowledged there were problems, including with recruitment and equipment.

He said: “There’s no doubt about it that the Royal Navy is undergoing a maritime renaissance, but its shortage of available vessels is deeply disturbing. The amount of things that actually work in the Royal Navy is quite disturbing.”

In August 2022, the navy’s new £3 billion aircraft carrier HMS Prince of Wales broke down off the Isle of Wight and the ship remains under repair.

Lord Houghton added that the RAF was suffering from a pilot shortage while the armed forces in general were “struggling” in the “global battle for talent”.

HMS Prince of Wales
HMS Prince of Wales, the £3 billion aircraft carrier which broke down off the Isle of Wight in August 2022 (Gareth Fuller/PA)

The committee, which is conducting an inquiry into armed forces readiness, also heard that stocks held for “major warfare” had been impacted by austerity in 2010 and, although Lord Houghton had warned about the potential for war with Russia in 2013, little had been done.

He said: “One of the ways in which we were able to cope with less money was to take a risk against the warfighting consumables or stocks that we held for major warfighting.

“Now, arguably, you could say that at the time – 2010 – that was a fair risk to take. Clearly, in the judgement of the government of the day, it was a fair risk to take.

“By the time I was writing my first letter to the prime minister on arrival (as chief of the defence staff), from memory, I was warning him then that the threats of the possibility that we might be called upon to cross the threshold of formalised warfare against an aggressive Russia were no longer latent but patent… and they were acknowledged.

“Was anything done about it? Not really.”

He said one of the reasons was that the British defence industry was not run as an “cooperative enterprise” but on the basis of fixed contracts, meaning companies did not maintain the capacity to produce more stocks at short notice.