I know, I know. But at least this one should be quick. The outgoing Prime Minister said it will be completed “within the next week”, and a new leader is expected to be in place by Friday, October 28.
This compares to the two-month election that followed Boris Johnson quitting in early July.
It means the UK is gearing up for its fifth prime minister in just over six years, underlining the unprecedented political instability in Westminster.
David Cameron resigned in the aftermath of the EU referendum, the fallout of which also saw off Theresa May. Mr Johnson stood down after being rocked by a series of well-publicised scandals.
So who are the runners and riders to take over the top job now?
A number of names have been pinging around the WhatsApp groups of Westminster. But some are more feasible than others.
Sir Graham Brady, the chairman of the 1922 backbench committee of Conservative MPs, said challengers will need nominations from at least 100 Conservative MPs to make it to the next stage of the race to replace Ms Truss.
That’s a big threshold to reach, and means a maximum of three candidates on the ballot paper for MPs to vote on. Sir Graham told reporters: “We fixed a high threshold, but a threshold that should be achievable by any serious candidate who has a prospect of going through.”
Tory party chairman Sir Jake Berry said Conservative HQ will be working with broadcasters to arrange one televised event so members can hear from the final two candidates before they vote in an online process.
Former chancellor Rishi Sunak is the bookie’s favourite. He previously lost out on the top job to Ms Truss, but subsequent events appear to have vindicated his warnings about the outgoing Prime Minister’s “fairytale economics".
His supporters are already making their voices heard. Scottish Tory MP Andrew Bowie tweeted: “There is only one person that can unite this party, get the economy on a firm footing. Only one with the plan to move us forward. And that is the same person I believed in over the summer. It has to be Rishi.”
Mr Sunak certainly has a public profile, thanks to the pandemic. But some think he stabbed Mr Johnson in the back when he quit as chancellor in the summer.
Remarkably, there are already reports Mr Johnson himself is considering throwing his hat in the ring. Could the former Prime Minister make a return? It might seem fanciful, but all the normal rules of politics have long since gone out the window.
Mr Johnson is hugely popular in some sections of the party, although not so much in others. He also still faces a Commons inquiry over whether he misled Parliament over ‘Partygate’.
Brendan Clarke-Smith, the MP for Bassetlaw, told the BBC Mr Johnson “has a mandate”. He said: “He delivered a historic, 80-seat majority, and I think with the turmoil we’ve got at the moment, we need somebody who can unite the party, somebody who can get us back in the polls there, and somebody who can actually be a winner. And for me, Boris Johnson is the man who ticks all of those boxes.”
Other names in the mix include Commons leader Penny Mordaunt. A former trade minister, with Cabinet experience in the defence and international development briefs, she ran to replace Mr Johnson with the catchy campaign name PM 4 PM.
Ms Mordaunt, a Royal Navy Reservist, previously said leadership “needs to become a little less about the leader and a lot more about the ship”. She came third last time, narrowly missing out on a place in the head-to-head phase, in which she backed Ms Truss over Mr Sunak. Some think Ms Mordaunt lacks experience, however.
John Lamont, the Scottish Tory MP for the Borders, tweeted: “We need the next Prime Minister to unite our country and win back voter trust. I hope @PennyMordaunt will stand. She is exactly the kind of calm, cool and collected leader we need right now.”
Ben Wallace, the defence secretary, could fancy his chances. He didn’t run in the leadership race over the summer and could be seen as a fresh face. Asked if he would consider running at the recent Conservative Party conference, he said: “I don’t rule it out.”
Mr Wallace, a former soldier, has won plaudits for his handling of the situation in Ukraine. His was anti-Brexit, but a key ally of Mr Johnson. He is also a former MSP for North East Scotland.
Bookies are also taking bets on Kemi Badenoch, the former equalities minister. She ran in the summer leadership contest and appeared to be targeting the anti-woke vote.
Suella Braverman has also been mentioned. She resigned as home secretary just a day ahead of Ms Truss’s resignation, lashing out at the PM’s “tumultuous” premiership and accusing the Government of “breaking key pledges” including on immigration policy.
A former Attorney General, she ran in the leadership race to replace Mr Johnson, promising “rapid and large tax cuts”, and saying she would suspend net-zero targets to deal with the energy crisis and pull the UK out of the European Convention on Human Rights.
She might attract support from the Tory Party’s right wing with her attacks on the "tofu-eating wokerati".
Other, perhaps less likely, contenders include Sajid Javid, the ex-chancellor and health secretary. Over the weekend, a Downing Street source described Mr Javid as “s**t” to a newspaper, so it’s safe to say he’s not universally admired.
Elsewhere, Chancellor Jeremy Hunt was quick to rule himself out as he focuses on calming the financial markets, and Michael Gove will also sit out the contest.