Rishi Sunak says July 4 election is a question of trust as he takes aim at Kier Starmer

In response, Mr Starmer told voters: “Together we can stop the chaos, we can turn the page, we can start to rebuild Britain.” 

At present, the opposition Labour party is about 20 points ahead in the polls, with Mr Starmer widely expected to become the UK's next prime minister after transforming his party since its historic election defeat almost five years ago.

A sodden Mr Sunak had to battle both the rain and the sounds of New Labour anthem 'Things Can Only Get Better' being blasted from beyond the Downing Street gates, as he said he would “fight for every vote” as he attempts to overturn a 20-point opinion poll deficit.

Mr Sunak said: “This election will take place at time when the world is more dangerous than it has been since the end of the Cold War.” 

He highlighted Vladimir Putin’s invasion of Ukraine, the tensions in the Middle East relating to the Israel-Hamas conflict, China’s efforts to “dominate the 21st century” and migration “being weaponised by hostile states to threaten the integrity of our borders”.

“These uncertain times call for a clear plan and bold action to chart a course to a secure future,” he said.

“You must choose in this election who has that plan.”

A July election is earlier than many in Westminster had expected, with a contest in October or November widely thought to have been more likely.

Mr Sunak’s announcement came after the Office for National Statistics said Consumer Prices Index (CPI) inflation slowed to 2.3% in April, down from 3.2% in March.

He said that inflation was now “back to normal”, meaning “the pressure on prices will ease and mortgage rates will come down” – although interest rates are actually a matter for the independent Bank of England.

It was “proof that the plan and priorities I set out are working”, Mr Sunak said, but he acknowledged “for some it might still be hard when you look at your bank balance”.

One reason for delaying the election might have been to allow Chancellor Jeremy Hunt to deliver another tax-cutting financial statement in the lead-up to the vote.

But official figures revealed borrowing for April overshot forecasts, hitting £20.5 billion, suggesting he would have had limited scope for pre-election giveaways.

But Mr Sunak said he had restored “hard-earned, economic stability”.

“The question now is how and who do you trust to turn that foundation into a secure future for you, your family and our country.” 

He added: “On July 5, either Keir Starmer or I will be prime minister. He has shown time and time again that he will take the easy way out and do anything to get power.

“If he was happy to abandon all the promises he made to become Labour leader once he got the job, how can you know that he won’t do exactly the same thing if he were to become prime minister?

“If you don’t have the conviction, to stick to anything you say, if you don’t have the courage to tell people what you want to do and if you don’t have a plan, how can you possibly be trusted to lead our country, especially at this most uncertain of times?” 

But Labour leader Mr Starmer said: “If they get another five years they will feel entitled to carry on exactly as they are. Nothing will change.” 

He promised a “new spirit of service”, putting the country before party interests.

“I am well aware of the cynicism people hold towards politicians at the moment, but I came into politics late, having served our country as leader of the Crown Prosecution Service, and I helped the Police Service in Northern Ireland to gain the consent of all communities.”

He added service was the “reason, and the only reason why I am standing here now asking for your vote”.