The prime minister told MPs on Thursday that replacing traditional guns with energy weapons would help solve the problem of troops running out of ammo, and that lasers were among "technologies that >The prime minister told MPs on Thursday that replacing traditional guns with energy weapons would help solve the problem of troops running out of ammo, and that lasers were among “technologies that will revolutionise warfare”.

“Our warships and combat vehicles will carry directed energy weapons, destroying targets with inexhaustible lasers. For them, the phrase ‘out of ammunition’ will become redundant," he told the Commons.

Mr Johnson said his defence modernisation package would “end the era of retreat” and “upgrade our capabilities across the board” when it came to the armed forces.

The prime minister has also announced the creation of a new Space Command wing of the military, and said he would give British troops the ability to overwhelm their enemies by launching “a swarm attack by drones”.

He also said the UK’s new aircraft carrier HMS Queen Elizabeth would next year lead a task group to East Asia, in a challenge to China that the prime minister described as “our most ambitious deployment for two decades”.

“We shall deploy more of our naval assets in the world’s most important regions, protecting the shipping lanes that supply our nation,” he said.

Mr Johnson announced that the Ministry of Defence would get a four-year financial settlement, in contrast to other government departments whose finances are only set to be guaranteed for a single year.

Labour leader Sir Keir Starmer said: “We welcome this additional funding for our defence and security forces. And we agree that it’s vital to end what the Prime Minister called, I’d say with complete lack of self awareness, an era of retreat.”

Sir Keir said that it was under Conservative-led government over the past decade that defence spending had fallen by £8bn in real terms and regular forces had fallen by a quarter, while a £13bn black hole had opened up in MoD equipment budgets.

“The additional funding today is on foundations that have been seriously weakened over the last 10 years,” said the Labour leader.

Sir Keir said that the announcement of additional funding before the publication of the planned integrated review of the UK’s defence priorities meant there was “no clarity” about the government’s strategy.

And he added: “How will this announcement be paid for?

“Such is the government’s handling of the pandemic that the UK has the sharpest economic downturn of any G7 country.

“Next week the Chancellor will have to come here and set out the consequences of that. So can the Prime Minister tell us today, will the commitments he’s made require additional borrowing, mean tax rises - and if so, which ones? - or will have money have to come from other departmental budgets?”

He challenged the PM to come clean on whether he would keep to the manifesto to spend 0.7 per cent of GDP on aid, warning that failure to do so “would not only undermine public trust, but also hugely weaken us on the global stage.”