Sir Keir Starmer slashes aid budget to increase defence spending to 2.5% of GDP by 2027

That will mean spending £13.4 billion more every year from 2027, something which Sir Keir acknowledged will require “extremely difficult and painful choices”.

He said he wants that figure to reach 3 per cent of gross domestic product during the next parliament.

But to fund it, development assistance aid will be slashed from its current level of 0.5 per cent of gross national income to 0.3 per cent in 2027.

Sir Keir said the plan amounts to “the biggest sustained increase in defence spending since the end of the Cold War”.

Taking spending on the security and intelligence services into account as well as defence, the budget will amount to a 2.6 per cent share of the economy from 2027.

“We must change our national security posture, because a generational challenge requires a generational response,” he said.

“That will demand some extremely difficult and painful choices.

“And through those choices, as hard as they are, we must also seek unity, a whole society effort that will reach into the lives, industries and the homes of the British people.”

Sir Keir will travel to Washington later this week for talks with the US president, who has repeatedly pushed for Europe to increase its defence spending.

The Government has a legal duty for aid spending to meet the United Nations target of 0.7% of gross national income, but that has not been the case since it was cut to 0.5% during the pandemic.

Sir Keir said cutting it to 0.3 per cent was “not an announcement I am happy to make” but “at times like this the defence and security of the British people must always come first, that is the number one priority of this Government”.

Aid organisations reacted with fury to the Prime Minister’s decision.

Romilly Greenhill, chief executive of Bond, the umbrella organisation for international development and humanitarian assistance groups, said: “This is a short-sighted and appalling move by both the PM and Treasury.

“Slashing the already diminished UK aid budget to fund an uplift in defence is a reckless decision that will have devastating consequences for millions of marginalised people worldwide.

“Following in the US’s footsteps will not only undermine the UK’s global commitments and credibility, but also weaken our own national security interests.

“Instead of stepping up, the UK is turning its back on communities facing poverty, conflict and insecurity, further damaging its credibility on the global stage.”

While former Labour Cabinet minister David Miliband, the current chair of the International Rescue Committee, said: “The UK government's decision to cut aid by £6bn in order to fund defence spending is a blow to Britain’s proud reputation as a global humanitarian and development leader.

“Today, an unprecedented 300 million people are in humanitarian need around the world. The global consequences of this decision will be far reaching and devastating for people who need more help not less.

“We recognise the complex challenges facing the UK government in today's unstable world. The UK aid budget is famed for its value for money, innovation and impact for those in the greatest need around the world.

“We don’t know where the aid cuts will fall, but we do know that current investments are meeting desperate needs.

“The danger is that without humanitarian help more people will flee their homes to seek security and global health will be severely compromised.

“Britain’s aid budget has been a vital part of Britain’s foreign policy for many years, tackling instability as well as poverty.”