Sir Keir Starmer would send “exactly the wrong message” on defence to Russia and North Korea if he wins the election, Rishi Sunak has warned.

The Prime Minister claimed he was “deeply” concerned by his rival’s decision not to match the Conservatives’ commitment to spend 2.5% of gross domestic product on defence.

He claimed if Labour wins the election, one of the first things Sir Keir would do is “head off to a Nato summit having cut British defence spending”.

Mr Sunak was speaking after Russian President Vladimir Putin visited North Korea and signed a new partnership deal alongside the country’s leader Kim Jong Un.

The agreement between Moscow and the hermit state includes a vow of mutual assistance if either is attacked.

Speaking to reporters at Sizewell B nuclear power station in Suffolk, the Prime Minister repeated his concerns of an “axis of authoritarian states, including Russia, Iran, North Korea and China, who are increasingly acting together in a way that threatens our values, our interests and our security”.

He added: “That’s why I made the decisions to increase investment in defence spending to 2.5% of GDP, because we’re living in the most dangerous and uncertain time that our country has known since the end of the Cold War.

“Just from the conversations I’ve been having at the G7, and the Ukraine peace summit, that is a view that is shared widely across the world, that’s why it’s the right thing to do to invest more in our defence, to keep everybody safe.”

Mr Sunak announced in April that the UK would up its defence spending to 2.5% of GDP by 2030 under his leadership.

Labour has faced questions if it would follow suit with the same plans, but senior opposition figures have only said they would make the commitment when public finances allow.

Keir Starmer and Rachel Reeves meet the public in Swindon
Labour Party leader Sir Keir Starmer and shadow chancellor, Rachel Reeves met shoppers and staff and discussed the cost of living with employees in Wiltshire (Stefan Rousseau/PA)

Mr Sunak added: “Keir Starmer has not matched that pledge and that deeply concerns me ’cause the first duty of government is to protect the country.

“In fact if Keir Starmer is elected, one of the first things he will do is head off to a Nato summit having cut British defence spending from the planned increases that I’ve announced.

“I think that sends exactly the wrong message, both to our allies, where we want to lead so that they invest more in their defence as well, but also to our adversaries, like Putin, and like the North Koreans, and actually we need to deter them with strength.”