Five more police officers allegedly placed bets on the UK general election date, a force spokesperson said Tuesday, as Prime Minister Rishi Sunak withdrew support from two Conservative candidates over the escalating scandal.

The row has overshadowed the closing stretch of campaigning as Sunak struggles to close his party's 21-point average poll deficit to Keir Starmer's Labour opposition before the July 4 vote.

London's Metropolitan Police said the Gambling Commission had informed it that five additional officers and a member of Sunak's protection team were believed to have gambled on the election date.

The protection officer was arrested this month on suspicion of misconduct in a public office and has been placed on restricted duties, the Met said.

The five newly accused have not been arrested and do not "work in a close protection role," the force added, saying "only one officer is under criminal investigation."

The development came as the Conservatives announced that "as a result of ongoing internal inquiries," it could no longer support Craig Williams or Laura Saunders as candidates.

The regulator is investigating the two over claims they bet on when the election would be held, and if they did so based on inside information.

Political bets are allowed in the UK but using insider knowledge to make them is against the law.

Nominations have closed so they will still appear on ballot papers.

Sunak, who has said he is "incredibly angry" over the claims, has come under mounting pressure in recent days from inside and outside his party to act on them.

He took the country by surprise on May 22 when he announced the date of the election six months before he had to.