Britain to have new PM by 5 September as Tory leadership rules announced

With just two contenders so far having the support of the 20 Tory MPs needed to get them on to the ballot, the nine remaining hopefuls were scrambling to shore up support by Tuesday night before knockout votes begin on Wednesday afternoon, with the first results announced later that day.

To speed up the competition, the 1922 Committee of Tory backbenchers on Monday opted to increase the number of backers that a candidate needed from eight to 20, and ruled that they would need at least 30 votes to get past the first round.

Those who struggle to reach the 20 threshold could be forced to pull out within 24 hours and instead pledge their support to one of the frontrunners.

Mordaunt was given a boost by polling for Conservative Home on Monday night showing that she was the preferred candidate among party members.

The final two should have been decided by the time the Commons goes into recess at the end of Thursday, Brady said, with some in-person and virtual hustings held during August and a new prime minister announced on 5 September.

As well as a bidding war on tax cuts, candidates have also vied to be most generous on defence spending. Overnight the former foreign secretary, Jeremy Hunt, made another major spending pledge to spend 3% of GDP on defence by 2027/28 and to cancel cuts to the Ministry of Defence in his first budget.

More candidates could yet enter the race, though are likely to face an uphill battle for nominations. The home secretary, Priti Patel, addressed senior members of the European Research Group on Monday night in a bid to win their endorsement in order to decide whether she should stand as a candidate.

Sources said she had vowed to ditch green levies and look again at the case for fracking, as well as arguing that she was the only candidate on the right of the party with the chance of winning an election. But she had not formally announced her candidacy by Monday night.

Baker has also encouraged his old ally Jacob Rees-Mogg not to run for the leadership. He was said to be considering doing do, but sources close to the Cabinet Office minister said he had ruled it out.

Zahawi, who carried on with his speech even after a woman fainted with a loud crash in a packed and sweaty basement venue in the Churchill War Rooms, said he would cut income tax from 20p to 19p next year, and to 18p in 2024.

He also promised to suspend all VAT and green levies on energy bills for two years to help people with energy costs.

In an earlier interview, Zahawi said he would finance tax cuts by getting every government department to cut their costs by 20%, which his aides were later forced to qualify meant reducing head count rather than departmental spending.