Labour is searching for a new leader, but how will the process work? Joe Willis finds out.

Who are the candidates?

Andy Burnham is MP for Leigh and the Shadow Health Secretary. He is a former Secretary of State for Health who was candidate for leader in 2010.

MP for Normanton, Pontefract and Castleford, Yvette Cooper, is the Shadow Home Secretary and former Secretary of State for Work and Pensions.

Jeremy Corbyn is the MP for Islington North.

Liz Kendall is the Shadow Minister for Care and Older People and MP for Leicester West.

How did the ballot work?

To be placed on the ballot, candidates needed the nominations of 35 MPs. An MP who nominates a candidate does not have to subsequently support or vote for that candidate. Some MPs stated that they nominated colleagues to ensure that candidate got onto the ballot paper to widen the leadership debate.

What happens now?

Labour uses a one member, one vote (OMOV) system. Nominated candidates will be elected by members and registered and affiliated supporters - each has a maximum of one vote.

Like previous Labour leadership elections, an alternative vote system will be used for the leader and deputy leader, rather than a first past the post basis as used for the General Election.

Voters pick a candidate as their first preference choice for the leadership, and a second preference choice in case their favourite fails to win. If a candidate gets more than half of the first preference votes, they win outright.

If not, the candidate who gets the fewest first preference voters is eliminated, and their votes are re-distributed according to the second preferences marked on the ballot paper. 

This continues ultimately until one candidate has half of the votes and wins the election.

Has this always been the way they've done it?

No, until the OMOV system was brought in by Ed Miliband, Labour had three electoral colleges (party members, MPs and MEPs, and trade unions and affiliated societies) which were each given equal weight.

It was changed after the Falkirk row when the union Unite was accused of rigging the selection.

Labour wanted to overhaul its relationship with the trade unions and limit their power over the party.

The new system means if you’re a member of a Labour-affiliated trade union and you want to vote, you have to register as a Labour supporter.

When will the vote take place?

Labour will announce who was the leadership race on September 12. Anybody wanting to vote will need to join join as a member, affiliated supporter or registered supporter by 12 noon on Wednesday, August 12.

On Friday 14 August, ballot papers will be sent out, with members able to vote by post or online. Votes need to be cast by 12pm on Thursday 10 September for them to count.

Who's going to win?

Good question. The bookies' favourite is Andy Burnham (11/8 with William Hill), closely followed by Jeremy Corbyn (6/4). Yvette Cooper is in third (11/4), with Liz Kendall the outsider (50/1).

However, some polls put left wing candidate Corbyn 20 points ahead of his rivals.

Things get complicated though as he is not expected to have enough first choice preferences for an outright win.

This means he will need to do well on second preferences - and research suggests he isn't doing nearly as well on second as he is on first preferences.

Why is it interesting?

The winner will aim to lead the Labour Party to victory at the 2020 General Election and would hope to become the country's next Prime Minister.

Jeremy Corbyn only made the ballot because supporters of other candidates 'lent' their votes to him to broaden the debate.

But it turns out his plans of investing in public services, ending austerity and getting rid of Britain's nuclear deterrent have proved quite popular with many Labour Party members.

Mr Corbyn's popularity has prompted the likes of Tony Blair, Neil Kinnock and Peter Mandelson to warn of the 'dire' consequences if he were to win - the former Sedgefield MP even suggested Corbyn followers "should get a heart transplant".

Even some Tory-supporting commentators have suggested a Corbyn win would be bad for their party.