The final weeks of the general election campaign have been overshadowed by a growing scandal over candidates and former MPs betting on the date of the general election, with some even placing a wager on losing their own seats.

Prime Minister Rishi Sunak has said he was “incredibly angry” to learn of allegations that Tory insiders were betting on the election and promised to “boot out” anyone found to have broken gambling laws.

Labour leader Sir Keir Starmer has also seen his party pulled into the scandal and said during a head-to-head debate with Sunak on Wednesday night that he suspended his party’s candidate “within minutes” of finding out they were being investigated.

He went on to criticise those involved, telling the BBC programme: “The instinct of these people to think the first thing they should do is try to make money, that was the wrong instinct, and we have to change that.”

He said Sunak had “delayed and delayed and delayed” and had been “bullied into” taking action, adding: “My candidates know I have the highest standards. They have seen by my actions the consequences.”

What are the rules for election betting for MPs?

It is not a criminal offence for a politician to place a bet on the outcome or timing of the general election, but it could become one if one is placed based on information not in the public domain.

Under the 2005 Gambling Act, it is an offence for anyone, including politicians, to use “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,” the law states.

This applies to any situation where someone may have advanced knowledge that is not public, such as a television official betting on the outcome of a reality TV show they work for or a footballer betting on the lineup of a match they are playing in.

However, the offence only applies if the individual placing the bet, or someone placing it on their behalf, is aware that the information is restricted.

For example, it may not be an offence if someone overhears a conversation or inadvertently sees something that leads to them placing a bet if they have no connection to the events in question.

Who are the Tory candidates accused of placing election bets?

The scandal broke when The Guardian revealed that Craig Williams, the Tory candidate for Montgomeryshire and Glyndŵr and Sunak’s closest parliamentary aide, was under investigation by the Gambling Commission for placing a £100 bet on a July election just three days before it was announced.

It was later revealed that Laura Saunders, the Tory candidate in Bristol North West, was also being investigated alongside her husband Tony Lee, the Conservative Party’s campaigns director.

Russell George, a Tory member of the Senedd representing the same constituency as Williams, was also being investigated, as well as the party’s chief data officer Nick Mason.

Both Williams and Saunders have since been suspended as the Conservative candidates for their respective constituencies.

The Sun has also reported that Tory candidate and ex-MP Sir Philip Davies, who is married to Cabinet minister Esther McVey, allegedly placed an £8,000 bet that he would lose his seat at the election. He is currently defending a majority of just over 6,000 votes.

On Tuesday evening, Scottish Secretary Alister Jack admitted he had placed three bets on the date of the general election, one of which was successful and netted him £2,100 in winnings.

Jack, who is not standing in the general election, said in a statement that the Gambling Commission had not contacted him about the bets and that he was “absolutely clear I have not breached any gambling rules”.

Who are the Labour candidates accused of placing election bets?

Labour has suspended Kevin Craig, the party’s candidate in Central Suffolk and North Ipswich, after it was revealed he was being investigated by the Gambling Commission for betting against himself in the upcoming election.

The party will also reportedly return £100,000 in donations that the businessman has made to the party since Starmer took over as leader, while Shadow Health Secretary Wes Streeting is said to be returning funds he donated for staffing costs.

A Labour Party spokesperson said that it “upholds the highest standards for our parliamentary candidates, as the public rightly expects from any party hoping to serve, which is why we have acted immediately in this case”.

Who else has been accused of placing election bets?

A serving Metropolitan Police Service officer who works as part of Sunak’s specialist protection unit has been arrested for alleged misconduct in public office after they placed five bets on the date of the general election.

The force has also confirmed that it has been passed information from the Gambling Commission relating to five further officers who also placed bets on election timing, although none of these individuals have been arrested.

“The Gambling Commission continues to investigate these matters. The officers have not been arrested but the Met’s directorate of professional standards has been informed,” the Met Police said in a statement.

The watchdog is also reportedly looking at a dossier of suspicious bets linked to the election date with winnings of more than £199 to find any links to Tory party members.

What are the Gambling Commission and Met Police investigating?

The Metropolitan Police has confirmed that it is now involved in the investigations on a “small number of cases” to “assess whether the alleged offending goes beyond Gambling Act offences to include others, such as misconduct in public office”.

“The Met is not taking over the investigation into bets on the timing of the General Election. The Gambling Commission will continue to lead the investigation into cases where the alleged offending is limited to breaches of the Gambling Act only,” it said.

The Gambling Commission has confirmed it is investigating multiple individuals in relation to breaches of the Gambling Act.

Those found guilty could face up to two years in prison, a fine, or both, although other sanctions such as the confiscation of winnings can be imposed at the gambling watchdog’s discretion.