Rishi Sunak has faced further questions on gambling by Conservative candidates on Friday as he sought to move on from the scandal, telling voters not to “sleepwalk to July 4”.

The Prime Minister launched the Tories’ Welsh manifesto where he acknowledged voters’ “frustrations” but told them the General Election is too important to be used to send the party a negative message.

In the Labour camp, Sir Keir Starmer has faced questions about his support for Jeremy Corbyn, after the party’s leader said his predecessor Jeremy Corbyn “would be a better prime minister” than “what we got – Boris Johnson, a man who made massive promises and didn’t keep them”.

He continued to face questions about his positions as Saturday’s newspaper headlines emerged, with Harry Potter author JK Rowling telling The Times she has a “poor opinion of his character” and Business Secretary Kemi Badenoch warning Labour could thwart Brexit, which she described as a “10 to 20-year project”.

On the campaign trail in Wales, Mr Sunak said: “I warn you, don’t fall into Labour’s trap, don’t sleepwalk to July 4.

“I know you want to send us a message, but this is not a by-election.”

He also said: “They want to give 16-year-olds a vote not because on principle they think that they are adults, but because they think they’ll vote for them.

“Once they have got power they will change every rule to make sure that they keep it.”

The Prime Minister took questions from journalists about allegations a string of people with links to the Conservative Party or Number 10 bet on the timing of the contest before he announced it.

Mr Sunak refused to be drawn on whether he is aware of other Conservative candidates or officials who placed bets on the date of the election, saying there are “multiple investigations” under way that are “independent” and “confidential”.

He added: “What I can tell you is, as I said, if anyone is found to have broken the rules, they should not only face the full consequences of the law, but I will ensure that they are booted out of the Conservative Party, too.”

Craig Williams, the party’s candidate in Montgomeryshire and Glyndwr and Mr Sunak’s parliamentary aide, admitted to having “a flutter” on the date of the election after it was disclosed he was under investigation by the Gambling Commission.

It has since been reported that another candidate, Laura Saunders, and her husband, Tory director of campaigning Tony Lee, were also facing a Gambling Commission investigation, while a member of Mr Sunak’s close protection team has been arrested and removed from operational duties over similar allegations.

The matter was referred to the Independent Office for Police Conduct (IOPC) which said, at this stage, the Metropolitan Police’s Directorate of Professional Standards should investigate.

Ms Saunders, the Conservative candidate for Bristol North West, said she “will be co-operating with the Gambling Commission” investigation, while Mr Lee took a leave of absence from his role with the party on Wednesday, just 15 days before the polls open.

Labour has called for both Mr Williams and Ms Saunders to be suspended as candidates.

A line graph showing the Conservatives continue to trail Labour significantly
(PA Graphics)

Speaking to journalists on Friday, Sir Keir Starmer accused Mr Sunak of a “total lack of leadership” over his decision not to suspend either candidate.

He said: “Of course, he should suspend these candidates. If they were my candidates, they’d be gone by now, out of the door. He needs to take tough action. He’s not even saying today whether there are more involved.”

The Gambling Commission confirmed its probe is into potential criminal offences, with a spokesperson saying: “Currently, the commission is investigating the possibility of offences concerning the date of the election.”

The watchdog noted that if someone uses confidential information in order to gain an unfair advantage when betting, this may constitute an offence of cheating under Section 42 of the Gambling Act, which is a criminal offence.

Rishi Sunak shakes hands with a man during the Welsh Conservatives manifesto launch
The gambling scandal overshadowed the launch of the Conservatives’ Welsh manifesto (Aaron Chown/PA)

Former prime minister Boris Johnson waded into the row over Sir Keir’s statements about Mr Corbyn, who is contesting the Islington North seat.

He wrote in his Daily Mail column: “Starmer must now be put remorselessly on the spot. He must take it back. You can’t back Corbyn and back Ukraine at the same time.”

Sir Keir set out his position in a GB News interview which aired on Friday evening and said: “Well, look, the last election, we had a very poor choice in 2019 and what transpired was obviously Jeremy Corbyn got rejected by the electorate – not the right person – and we’ve expelled him now from the Labour Party, so that’s how far we’ve changed the Labour Party.

“Boris Johnson was elected as prime minister and a number of years later was booted out of Parliament for breaking the rules.

“That’s why I’ve been so determined to change the Labour Party, to always say country first, party second, and make sure at this election there is a real choice between continuing with the Tories or now turning a page and rebuilding the country with Labour.”

Towards the end of the week, on Saturday’s front pages, it emerged JK Rowling accused Labour of turning its back on women. She wrote in the newspaper: “The women who wouldn’t wheesht (be quiet) didn’t leave Labour. Labour abandoned them.”

Sir Keir had said on Thursday’s Question Time’s leaders’ special that “there are some people who don’t identify with the gender that they are born into and they go through a lot of anxiety and distress, and my view in life is to respect and give dignity to everyone, whatever their position”.

On Brexit, Ms Badenoch told The Telegraph: “This is a 10 or 20-year project. We’ve just started. It’s like building a house and someone comes in and says oh, it’s not done yet, he’s failed.”

The Labour Party manifesto commits to “no return to the single market, the customs union, or freedom of movement”.