Liz Truss announced her resignation after a turbulent six weeks in office. (PA)/Photo Courtesy

The UK will have a new prime minister by the end of next week after Liz Truss announced her resignation. Her premiership will be the shortest running in British history, having only stepped into 10 Downing Street on 6 September.

What little was left of her authority crumbled on Wednesday following home secretary Suella Braverman's resignation and reports of "manhandling" and "bullying" of Conservative MPs over a vote on fracking.

Now, key details of the leadership race have been confirmed: candidates will need the backing of 100 MPs to be in the running; the Tory membership could still get a say via electronic voting; and one the favourites to emerge is none other than Boris Johnson.

Here's what we know - and what happens next:

What happens next?

Sir Graham Brady, chair of the 1922 committee of Conservative backbenchers and whose role means he is responsible for overseeing leadership elections and votes of confidence, told reporters he expected a new leader to be in place before Friday, 28 October.

This would be just in time before the upcoming fiscal statement on Halloween, setting out a medium-term fiscal strategy and independent economic forecasts.

Read more: How an almighty migration row led Suella Braverman to turn against Liz Truss

Brady confirmed that nominations to be the next leader will open on Thursday evening.

He said hopefuls will need the backing of at least 100 MPs by Monday at 2pm to be in the running.

The first ballot of MPs will then be held between 3.30pm and 5.30pm that day.

If there are three candidates, the candidate with the fewest number of votes will be eliminated - with the result announced at 6pm.

If two candidates remain, MPs will hold an indicative vote between 6.30pm and 8.30pm, with the result announced at 9pm.

Tory party members will then have the opportunity to vote on their preferred candidate online, with the ballot closing at 11am on Friday 28 October and the result announced later that day.

However, if only one candidate reaches the 100 MP threshold needed on Monday, they will automatically become the next leader of the Conservative party and the next PM.

The process will be considerably speedier than the previous leadership contest, which ran from 13 July to 5 September – longer than Truss' time in Number 10.

Who is in the running?

With the Conservative Party now bitterly divided, there will be some struggle finding a unity candidate to replace Truss, who succeeded Boris Johnson on 6 September.

Some of the main contenders to replace Truss include Rishi Sunak, who came second to her in the last Conservative Party leadership race.

Penny Mordaunt is also another favourite, but chancellor Jeremy Hunt is understood to have ruled himself out.

Former leadership contender Tom Tugendhat has also said he will not stand, while other figures who have been suggested include Kemi Badenoch, Kemi Badenoch and Ben Wallace.

There is speculation that Boris Johnson could attempt a return to Number 10.

According to The Times, Johnson will announce his intention to run shortly, and considers his decision to be "a matter of national interest".

A number of Conservative MPs have already backed him to take over, leading to widespread criticism from opposition figures.

Will Conservative Party members definitely have a say?

Tory members will only get to vote on a candidate if more than one leadership hopeful reaches the 100 MP threshold needed to qualify for the leadership contest.

Allowing the members to have a final say on the next leader could pave a route back for Johnson, should he reach the 100 MP threshold, with polling in August revealing 53% of Tory members believed he should have remained PM. By James Hockaday and Nadine Batchelor-Hunt, Yahoo News