British Prime Minister Boris Johnson is facing increased pressure to resign over "partygate" and accusations that he intervened to help evacuate animals from Afghanistan while people who had previously worked for the British were abandoned.

Johnson has dismissed the reports that No. 10 was involved in the Nowzad charity flight efforts as "total rhubarb."

Tom Tugendhat is reportedly favored by centrist Tory MPs to replace Johnson, with the former soldier and MP for Tonbridge and Malling confirming on Saturday that he would run for leader if there was a contest soon, adding it would be a "huge privilege" if he became prime minister.

But who else is being suggested? Here are some of the potential candidates.

Rishi Sunak

Rishi Sunak has been installed by bookmakers as an early favorite to replace Boris Johnson. He was named Chancellor shortly before the coronavirus pandemic began and created the furlough scheme and other financial support systems during the lockdown.

Last week, Sunak said he believed the prime minister's words over his knowledge of the alleged Downing Street parties and added that he "wasn't going to get into hypotheticals" when asked if Johnson should resign if he is found to have lied to Parliament.

Sunak has been out of the media spotlight this week, with reports suggesting he is taking an "arms-length" approach to the prime minister.

Liz Truss

Liz Truss prompted comparisons with former prime minister Margaret Thatcher in November after she was pictured sitting in an Army tank during a trip to Estonia.

The former international trade secretary was promoted to the Foreign Office in September last year after Dominic Raab was criticized for his handling of the Afghanistan crisis.

During an interview on BBC Breakfast on Wednesday, Truss said she was "100 per cent supportive" of the prime minister and wants him "continuing doing the job."

Jeremy Hunt

Jeremy Hunt has held numerous Cabinet roles, his most recent being foreign secretary in Theresa May's government until May 2019. He launched a leadership bid in 2019 after May's departure but came second to Johnson.

In an interview last week with The House magazine, the former health secretary reportedly denied actively considering a run, before adding: "I won't say my ambition has completely vanished, but it would take a lot to persuade me to put my hat into the ring."

Penny Mordaunt

Penny Mordaunt could be a potential successor for Johnson despite recent legal threats against her and the Government by Tory donor Alexander Temerko.

Temerko said he would bring unspecified legal action against Mordaunt personally, describing her as the "biggest threat to security" after she successfully campaigned against a 1.2 billion pound ($1.6 billion) cross-Channel power cable project Aquind, a company he is a director of, has proposed. Her response was: "I'm happy to be judged on my record."

Mordaunt has held several Cabinet positions including defense secretary andis reportedly "well-liked" among the so-called Red Wall MPs elected at the 2019 general election.

Sajid Javid

Sajid Javid is also a seasoned Cabinet member, having served in David Cameron and Theresa May's governments.

He outlined his political aspirations in 2016 and 2019 by launching leadership bids. In 2016, he ran a joint campaign with Stephen Crabb but the pair later withdrew. In 2019 he came in fourth behind Johnson, Hunt and Michael Gove.

Since his appointment as Health Secretary in June last year, Javid has supported Johnson but admitted on Sky News that Tory grandee David Davis calling for the prime minister to step down was "damaging" for the government.

Nadhim Zahawi

Nadhim Zahawi has been a familiar face during the pandemic after being appointed vaccine minister in November 2020. His success in the role – which saw him providing updates to Parliament on the vaccine rollout and hosting Downing Street press conferences – led to apromotion to Education Secretary during the Cabinet reshuffle last September.

He has backed the prime minister during interviews, and said during an interview on BBC Radio 4's Today program that he believed Johnson was safe in his role "because he's human and we make mistakes."

Michael Gove

Like Javid, Michael Gove has held a series of Cabinet positions and launched a leadership bid in 2019 after Theresa May resigned. He finished third. In 2016, he announced he would back Johnson as new Tory leader and prime minister following Cameron's resignation, only to announce he was running himself two hours before Johnson made his leadership pitch official, scuppering his friend's chances.

Gove has denied Johnson should tender his resignation over the Downing Street party saga and claimed there is "no evidence of any abuse of levelling up funding" after Christian Wakeford, an MP who defected to Labour, alleged he was warned funding could be cut for a new school in his constituency if he rebelled in a vote over free school meals.

Gove also told MPs on Monday he was "solid, 100%, totally behind the prime minister."

Tom Tugendhat

Tom Tugendhat has been critical of the government, most recently over its handling of the withdrawal of troops from Afghanistan.

The former soldier, who served in both Afghanistan and Iraq, has been tipped before as a potential option to take over as party leader, with reports of a senior Tory MP describing it as a "relief" if he took over.

On Saturday, he was asked if he would still like to be prime minister, after expressing an interest in the past, and said: "It would be a huge privilege."