LONDON - British Prime Minister Rishi Sunak said he was "incredibly angry" to hear that three of his party colleagues were being investigated over allegedly placing bets on an early announcement of the general election.

On another chaotic day for the governing Conservatives, the party's campaign director took a leave of absence, linked to an investigation around bets being placed on the timing of the vote before it was announced.

"I was incredibly angry to learn of these allegations. It's a really serious matter. It's right that they're being investigated properly," Sunak said during a televised debate. "I want to be crystal clear that if anyone has broken the rules, they should face the full force of the law."

Polls indicate Britain is on course to elect a centre-left Labour government led by Keir Starmer, ending 14 years of rule by the Conservatives, and some polls have suggested Sunak's party could be heading to a historic defeat.

The allegations that a second Conservative candidate was being investigated by Britain's gambling regulator and may have attempted to profit from their political knowledge of the timing of the election is the latest setback in Sunak's faltering efforts to stay in Downing Street.

The BBC named the candidate as Laura Saunders, who is running to be the member of parliament for Bristol North West, and said her husband, campaign director Tony Lee, was also being investigated.

The Conservative Party earlier said that its director of campaigning "took a leave of absence" on Wednesday.

Sunak said if anyone has been found to have broken the rules they should face the "full consequences of the law" and would be "booted out" of the party.

Neither Lee nor Saunders could be reached for comment and the gambling regulator did not name those it was investigating. Placing bets with insider knowledge is a crime.

Another candidate has already apologised for placing a bet on the timing of the election on July 4 before it was officially announced.

'VERY TOUGH'

British finance minister Jeremy Hunt on Thursday said it would be "very tough" for the Conservatives to win the election, after opinion polls predicted a landslide for Labour.

Asked at a Times newspaper event whether the Conservatives could win, Hunt said: "It's going to be very tough.

"I don't think any of us would pretend that is the most likely outcome. We can certainly do a lot better than the polls are suggesting and we are working very hard to do so."

Starmer is set to become prime minister with a 200-seat parliamentary majority, the biggest for any party for a century, according to the latest poll by YouGov.

A separate poll predicted Sunak could become the first British prime minister in history to lose his own seat in a national election. Hunt's seat is also under threat.

The Conservatives were already far behind in opinion polls when Sunak called the election, hoping that an upturn in economic data would help his party narrow the gap with Labour.

But that has failed to materialise from a Conservative campaign beset by missteps, starting with Sunak's inauspicious announcement of the election in pouring rain, and most notably leaving D-Day commemorations in France earlier than other world leaders, which led to widespread criticism.

(Reporting by Paul Sandle, Andrew MacAskill, Sachin Ravikumar, Muvija M and William James; Editing by Janet Lawrence and Daniel Wallis)