James Cleverly accused Sir Keir Starmer of an “act of vandalism” on defence spending as he repeatedly attacked the Prime Minster during his pitch to become the next leader of the Conservative Party.

In what was billed as a major speech in his campaign, the former home secretary said his priorities as prime minister would be to boost national security, reduce migration and restore “confidence in capitalism”.

Committing to spending three per cent of GDP on defence if he became prime minister, he accused Sir Keir of recklessness for ditching the previous government’s timetable for spending 2.5 per cent.

The Braintree MP said: “Starmer, in an act of vandalism, has scrapped that.

“You cannot penny-pinch your way to peace. Security is delivered through strength. By planning for the worst, not hoping for the best.

“We will send a signal to our enemies that the British are prepared. We will not leave the field.”

Mr Cleverly added that the UK currently spends “ten times” more on health, welfare and pensions than on defence.

He added: “Starmer says we can’t afford to spend more on defence. I say we can’t afford not to.”

The attacks on the Prime Minister continued as Mr Cleverly insisted that only a united Conservative Party would be taken seriously by a public he believes will quickly lose faith in Labour.

He said: “We must unite if you want the British people to listen to us again, so when they are fed up, as they inevitably will be with Starmer’s inept, high-taxing, red tape-loving, big state, crony-filled government, they will look to us again to be the change that they want to see in this country.”

Mr Cleverly said his changes to visa schemes are now “cutting migration by half”, adding that “asylum applications fell, the backlog was cleared, the grant rate fell and deportations” when he was home secretary.

He added that as prime minister he would use his “contacts and reputation” to “resurrect” the Rwanda partnership as a deterrent to illegal migration.

Mr Cleverly accused Labour of an “arrogant and callous disregard for diplomatic niceties that bind the world”, claiming the Government informed the media that the scheme would be scrapped before notifying the Rwandan government.

Outlining his third priority, Mr Cleverly said “we must address a crisis on confidence in capitalism”.

He added: “We need to unlock real growth again, and we need to show young people that free markets, not planned economies, are their friends.

“We need to turn them into capitalists. Too many people think that high taxes help them rather than hold them down.

“They think that more regulation protects them, rather than benefiting incumbent suppliers.

“Protectionism drives up costs for them, drives down choice for them, benefits the already rich, harms the aspirational poor.

“I will make boosting our economic growth a defining mission of our party.”

Mr Cleverly also vowed to abolish stamp duty and bring the welfare budget down while being “honest about the trade-offs”.

He said: “We should enable self-reliance, family first, resilience and community solutions.

“Tax and subsidise cannot be our mantra anymore, so we must think and act like Conservatives again.”

The field of six candidates – which also includes Kemi Badenoch, Robert Jenrick, Dame Priti Patel, Tom Tugendhat and Mel Stride – will be whittled down to four by the time of the Conservative conference at the end of the month.

After that, MPs will carry out further rounds of voting to select two final candidates for the Conservative members to choose between, with the result announced on November 2.