Rishi Sunak and Sir Keir Starmer return to the campaign trail on Thursday after they clashed over the Westminster betting row in their final televised head-to-head debate ahead of the General Election.

The Labour leader accused the Prime Minister of being “bullied” into taking action in the scandal, while Mr Sunak repeatedly warned voters not to “surrender” to Labour’s tax and migration plans in the heated exchange.

With the polls showing the Tories heading for an electoral drubbing with just a week to go until July 4, Mr Sunak used the BBC debate to hammer home his claim that Sir Keir “is not being honest with everyone about his plans to raise their taxes”.

He reiterated the much-disputed claim that taxes would rise by £2,000 under a Labour government, which Sir Keir dismissed as a “lie”.

The leaders are likely to face further questions on the deepening gambling saga, as it emerged the Metropolitan Police will lead on investigating a “small number of cases” related to betting to look into potential “misconduct in public office”.

And Sir Philip Davies became the latest Tory candidate to be accused of gambling on the election.

He reportedly bet £8,000 against himself holding his marginal Shipley constituency, according to The Sun.

At least five Conservatives are being investigated by the Gambling Commission as part of its inquiry into wagers on the timing of the July 4 poll.

Mr Sunak on Tuesday caved to mounting calls to withdraw support for two parliamentary candidates facing an investigation by the regulator: his parliamentary aide Craig Williams and Laura Saunders.

Ms Saunders’ husband, the Conservative Party’s director of campaigning Tony Lee, has taken a leave of absence, as has Tory chief data officer Nick Mason, while Welsh Tory Senedd member Russell George is also facing a probe by the gambling watchdog.

Labour has also been dragged into the row, suspending candidate Kevin Craig after he was investigated by the regulator for betting on himself to lose his contest in Central Suffolk and North Ipswich.

General Election campaign 2024
Host Mishal Husain with Rishi Sunak and Sir Keir Starmer during their BBC head-to-head debate in Nottingham (Phil Noble/PA)

Sir Keir said “you have to lead from the front on issues like this”, noting that he had suspended Mr Craig “within minutes”.

“The Prime Minister delayed and delayed and delayed until eventually he was bullied into taking action,” he said.

The Met said it would lead on investigating “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” and provide more information on Thursday.

A Met spokesperson said: “The Gambling Commission will continue to lead the investigation into cases where the alleged offending is limited to breaches of the Gambling Act only.

Graph showing polling averages of the main parties from February 25 to June 25
(PA Graphics)

“Met detectives will lead on investigating 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.”

In the last major set piece event before polling day, the Tory and Labour leaders also traded barbs over immigration, women’s rights and benefits bills.

Sir Keir drew applause from the studio audience when he accused his Conservative rival of being “out of touch” when it came to welfare benefits.

Mr Sunak fired a barrage of criticism at the Opposition leader over migration, claiming “people smugglers are going to need a bigger boat” because of his plans to scrap the Rwanda deportation scheme.

On Labour proposals to strike returns deals with other countries, Mr Sunak asked: “Will you sit down with the Ayatollahs? Are you going to try to do a deal with the Taliban? It’s completely nonsensical – you are taking people for fools.”

Loud protests were heard from outside the Nottingham debate venue as the duo faced off against each other.

The Liberal Democrats said “the audience spoke for the nation” when one man asked the two leaders: “Are you two really the best we’ve got to be the next prime minister of our great country?”

Sir Keir emerged as the winner of the TV clash according to a More in Common snap poll, with 56% of viewers preferring him and 44% choosing Mr Sunak. But a YouGov snap poll suggested viewers were split 50-50 over the victor.

Mr Sunak is campaigning in the East Midlands and Yorkshire on Thursday, after a two-day hiatus for the Emperor and Empress of Japan’s state visit and preparations for the debate.

Sir Keir is joining the Labour battle bus in the North West and West Midlands to promote Labour’s plans to “turbocharge” careers advice and work experience in schools.

Lib Dem leader Sir Ed Davey’s action-packed campaign tour continues as he calls for an emergency health budget after the election, while junior doctors in England start their five-day walkout in their long-running pay dispute.