With UK leader Liz Truss quitting, here are the top contenders to replace her

LONDON — British Prime Minister Liz Truss resigned Thursday, bringing to a close a brief 44-day tenure mired by "mini-budget" chaos, economic turmoil and weeks of political infighting.

Speaking outside Downing Street, Truss said she had delivered her resignation to King Charles after meeting with Graham Brady, the leader of the Conservative Party's 1922 Committee, earlier Thursday.

"Given the situation, I cannot deliver the mandate on which I was elected by the Conservative Party," she said in a brief speech Thursday afternoon.

The prime minister's departure follows days of high level resignations, and a growing number of Conservative members of parliament (MPs) publicly calling for Truss' resignation.

Truss said she will remain in place as caretaker prime minister until a successor is named, with a leadership contest expected to take place over the next week.

Here are the main contenders for the top job:

Rishi Sunak, Britain's former finance minister and Truss' main opponent in this year's Conservative Party leadership race, is now seen as a favorite to replace her.

Despite losing to Truss in the final round of voting by Tory members, he was the top choice among party MPs and is considered a safe pair of fiscal hands. Indeed, after being berated by Truss during the race as a voice of Treasury orthodoxy, his critique of the PM's "unfunded tax cuts" appears to have been vindicated.

The 42-year-old, who is credited with steering the U.K. economy through the height of the Covid-19 pandemic, is seen by supporters as well-placed to lead the country through its worsening cost-of-living crisis. However, some have questioned his ability to reunite the splintered Conservative Party, having played a key role in Boris Johnson's ousting, and being implicated in controversy over his wife's tax status.

As such, some Conservative backbenchers have proposed that a more politically palatable option would be for Sunak to form a joint ticket with fellow leadership contender Penny Mordaunt, with the pair thought to garner enough support together to secure MP backing without the need for a lengthy members' vote.

Former Defense Secretary Penny Mordaunt surged to prominence during the summer's leadership race, before finishing in third place to Truss and Sunak.

Broadly seen as a consensus candidate, Mordaunt was second to Sunak in MP voting until the final round of the race, and has since maintained links with Tory MPs in her current role as leader of the House of Commons.

The 49-year-old also escaped largely unscathed from the controversy surrounding Johnson's departure, and has since demonstrated her leadership prowess in the chaotic early weeks of Truss' premiership.

On Monday, she spoke to the House of Commons on behalf of Truss regarding the sacking of former Finance Minister Kwasi Kwarteng. But she has also distanced herself from Truss economically, criticizing the PM's stance on key policies such as welfare benefits.

Despite being ousted from office just three months ago, some Tory MPs have suggested that former PM Boris Johnson could return to the top job.

Former culture secretary and close Johnson ally Nadine Dorries tweeted Thursday that he was the only MP with "a mandate from party members and the British public," having won the 2019 General Election.

Johnson previously enjoyed high levels of popularity until losing credibility in the final months of his premiership amid political scandal around Covid-19 rule-breaking and his links to disgraced MP Chris Pincher.

The 58-year-old has not spoken recently on plans for a second leadership bid, but in his parting speech he alluded to a future return to office with the words: "Hasta la vista, baby" or "see you later."

Defense Secretary Ben Wallace has kept a relatively low profile amid Tory party furor while winning respect for his role in leading the U.K.'s support for Ukraine.

Popular among MPs, he was seen as a favorite to replace Johnson, but ruled himself out of this summer's leadership race citing discussions with "colleagues and family."

It is unclear whether he would run this time, having told The Times newspaper Tuesday that he wanted to remain in his current post. However, he also signaled that he would likely quit the job if the government did not commit to his defense spending targets.

Britain's new Finance Minister Jeremy Hunt, brought in to replace Kwasi Kwarteng, is considered the most powerful figure in government after he came in to overhaul Truss' economic plan and calm chaotic markets.

The 55-year-old is seen as a stable option, having previously held several senior government positions, including foreign secretary, health secretary and culture secretary. However, he has previously fallen short in a series of leadership bids, and on Thursday reportedly extracted himself from future runs.

On Monday, Hunt hinted that he would not run, telling Sky News: "I rule it out, Mrs Hunt rules it out, three Hunt children rule it out."

The Conservative Party will be keen to avoid a calling a General Election ahead of the 2025 deadline, with the latest opinion polls suggesting that the Tories would suffer a landslide defeat.

However, if Conservative MPs can't reach a consensus vote on a future leader, it is possible that the U.K. would go to the polls.

Opposition Labour leader Keir Starmer on Thursday renewed calls for an immediate General Election, saying the government was too mired in "political squabbles" to lead the country.

Scotland's First Minister Nicola Sturgeon echoed those calls, calling an election a "democratic imperative."

According to an Opinium poll released over the weekend, if a general Election were called now, Labour would secure 411 seats to the Conservative's 137, marking a sizeable defeat not seen since 1997.