Kemi Badenoch was knocked out of the race to become Britain's next prime minister on Tuesday, prompting a 24-hour scramble among the three remaining candidates to win over her supporters before the final round of balloting by Tory MPs.
The fourth round of voting saw former chancellor Rishi Sunak top the poll with 118 votes, all but guaranteeing that he will be one of the final two options presented to Conservative Party members.
Ms Badenoch, a former equalities minister on the right of the party, was eliminated after coming last with 59 votes but her allies can expect a day of heavy lobbying from the Truss and Mordaunt campaigns as they wrestle for second place.
The right flank of the party that favoured Ms Badenoch would seem a more natural fit for Ms Truss, but movements between rounds have been hard to predict and Wednesday’s vote remains wide open.
The rivals for second place immediately weighed in with glowing tributes to Ms Badenoch. Ms Mordaunt said she had “electrified the leadership contest with her fresh thinking and bold policies … she and I both know that the old way of government isn’t working as it should.”
A spokesperson for the Truss campaign said Ms Badenoch had "run a fantastic campaign and contributed enormously to the battle of ideas throughout this contest".
The fourth round was held after backbench MP Tom Tugendhat, a former soldier seen as a moderate in the race, was eliminated from the contest on Monday.
Although his supporters had been expected to lean towards Mr Sunak or Ms Mordaunt, it was Ms Truss who made the biggest progress — boosting her hopes of jumping into second in Wednesday's ballot.
A prominent Truss backer, backbench MP Dehenna Davison, said: “The momentum is firmly on Liz Truss's side.”
Once two candidates are left standing, postal ballots will be sent to the roughly 200,000 Conservative members and hustings held across the country before a winner is announced in September.
Ms Truss had made a play for Mr Tugendhat's votes on Tuesday by echoing his promise to spend 3 per cent of GDP on the military by 2030 in the face of growing hostility from Russia and China.
Cabinet minister Anne-Marie Trevelyan was one of the Tugendhat backers won over by Ms Truss, whom she described as bringing "strength to deal with the tough choices".
Ms Mordaunt has also talked up her military links as a naval reservist and short-lived defence secretary but has not committed to the 3 per cent threshold.
She instead focus on the economy on Tuesday, saying she would take on outgoing leader Boris Johnson's north-south equality agenda by improving apprenticeships, rail links and energy investments.
One of her supporters, former minister Andrea Leadsom, said testy exchanges between Ms Badenoch and Ms Mordaunt in TV debates did not mean that the loose votes could not fall for Ms Mordaunt in the final round.
"Leadership hustings are a brutal time... but the reality is Penny and Kemi have a strong relationship," she told Sky News. "And it's simply not true that all MPs vote as a bloc. Kemi doesn't command the bloc vote."
Mr Sunak meanwhile sought to position himself as a defender of the Union by highlighting billions of pounds he routed to Scotland when he was chancellor.
While candidates battle for Ms Badenoch's votes, another question is whether Mr Sunak's camp could try to influence the battle for second place by lending votes to a preferred opponent.
The Sunak campaign denied having used such tactics in earlier rounds. Prime Minister Boris Johnson was rumoured to have engaged in similar manoeuvres during the last leadership race in 2019.
At Downing Street, Mr Johnson chaired what was expected to be his final cabinet meeting and was presented with first-edition copies of Winston Churchill's books on the Second World War.
Mr Johnson ensured on Monday that he could stay in office until the end of the contest by winning a confidence vote in the House of Commons, defeating a Labour attempt to oust him sooner.
That led to another twist in the leadership race on Tuesday as backbench MP Tobias Ellwood, a Mordaunt supporter, was suspended from the Tory ranks for having failed to show up for the vote.
Mr Ellwood, a longstanding critic of Mr Johnson, blamed air travel chaos after saying he was unable to get home from a visit to Moldova.