British Chancellor Nadhim Zahawi and former cabinet minister Jeremy Hunt have been eliminated from the race to succeed Prime Minister Boris Johnson after the first round ofvoting by members of the ruling Conservative Party.

Rishi Sunak, whose resignation as chancellor helped trigger the Conservative leadership race, topped the ballot, with Trade Ninister Penny Mordaunt ahead of Foreign Secretary Liz Truss.

Senior backbencher Tom Tugendhat, Attorney General Suella Braverman and former Equalities Minister Kemi Badenoch also progressed to the final six candidates.

Zahawi and Hunt, who has held the offices of health and foreignsecretary, both failed to get the 30 votes required to get to the next stage.

Sir Graham Brady, the chairman of the Conservative 1922 committee overseeing the contest, read out the results in a crowded Committee Room 14 in the House of Commons.

Sunak was on 88, Mordaunt on 67, Truss, 50, Badenoch, 40, Tugendhat, 37, and Braverman squeaked through on 32.

Zahawi, brought in by Johnson after Sunak's resignation, got 25 andHunt only 18.

Truss sought to unite the right of the Conservative Party, also known as the Tories, as subsequent voting from Thursday will eliminate the least popular candidate until two are left.

"Now is the time for colleagues to unite behind the candidate who will cut taxes, deliver the real economic change we need from day one and ensure Putin loses in Ukraine," a spokeswoman for the Foreign Secretary said.

The first round of voting came after Downing Street was forced to deny running a "stop Sunak" smear campaign as the battle grew increasingly bitter.

The caretaker Prime Minister's press secretary insisted that Johnson is "staying neutral" despite his remaining arch-loyalists throwing their support behind Truss.

Two of them, Nadine Dorries and Jacob Rees-Mogg, announced their backing and stepped up their public criticism of Sunak after leaving Johnson's cabinet meeting.

Dorries, the Culture Secretary, accused the former chancellor's campaign of deploying "dirty tricks" to benefit his campaign and backed Truss as the Brexiteers' candidate.

Brexit Opportunities Minister Rees-Mogg accused Sunak of havingimplemented "economically damaging" policies.

Asked if No 10 is involved in an anti-Sunak operation as the first round of voting loomed, Johnson's press secretary bluntly said: "No."

She declined to say whether Downing Street remains supportive of the former chancellor, whose resignation helped end Johnson's grip on No 10.

The press secretary said she did not know whether Johnson discussed backing Truss with his allies before they made their public declaration in Downing Street.

"He's staying neutral in this contest," the spokeswoman said.

Rees-Mogg argued that the Foreign Secretary is "fiscally on the right side of the argument," unlike Sunak.

The minister told Sky News that Truss "opposed the endless tax rises of the former chancellor, which I think have been economically damaging, I also was opposed to (them) in Cabinet."

He also said Truss - who voted Remain in the 2016 European Union referendum - is more willing to take advantage of Brexit than Leave-voting Sunak.

Transport Secretary Grant Shapps, who abandoned his own leadership bid to back Sunak, denied claims from Dorries that the campaign has engaged in dirty tricks.

"Simply, in this case it just didn't happen," he said.

Meanwhile, trade minister Mordaunt officially launched her campaign by telling colleagues who had been fearful of losing their seats under Johnson's leadership that she is their "best shot" at winning the next election.

"I'm the candidate that Labour fear the most - and they're right to," she told Conservatives at Westminster's Cinnamon Club.

Seen as one of the frontrunners in the race, Mordaunt declined to describe Johnson as a good Prime Minister, instead thanking him for delivering Brexit.

Mordaunt insisted she is "very different" from Johnson but indicatedshe would not call an early general election to win her own mandate if she entered No 10.

The naval reservist and former defence secretary pledged to return totraditional Conservative values of "low tax, small state and personalresponsibility."

She said she stands by the Conservative manifesto commitment to meet the Nato target for defence spending of 2% of GDP and increase it by 0.5% above inflation every year.

She won the backing of Sir Mike Penning, who resigned as Conservative Party vice-chairman to campaign for her.

"I think the momentum is still going with her," he told Sky News.