In the Red Corner

The Candidate: David Miliband

The Organisation: Progress, the Blairite magazine and campaign group previously led by Peter Mandelson

The Thinkers: Phil Collins (former No 10 adviser and speechwriter) and Richard Reeves (new director of the Demos think tank and former special adviser to Frank Field)

Cabinet backers: James Purnell, John Hutton Popular appeal: Instantly recognisable. Women like him

Back-bench support? Doubts about loyalty but centre right trusts him

In the Even Redder Corner

The Candidate: Jon Cruddas

The Organisation: Compass, increasingly influential left-wing campaign group within the Labour Party

The Thinkers: Neal Lawson (founder of Compass and managing editor of the Labour journal Renewal) and John Harris (pop music writer and Guardian columnist)

Cabinet backers: None Popular appeal: A "bit of a lad". Unions like him, but an unknown quantity

Back-bench support? Liked by traditional Labour MPs and old Labour diehards, but modernisers see a dangerous lefty

Read "The factions square up"
By Martin Bright