Harriet Harman, Ed Balls and Yvette Cooper are expected to get big roles after the elections Labour will reveal the 19 MPs who will join new leader Ed Miliband’s shadow cabinet on Thursday.
In opposition, the party’s top team is voted in by its MPs although the leader gets to allocate specific jobs.
Voting closes on Thursday and ballots will be counted from 1700 BST with an announcement expected hours later.
Forty-nine MPs, including ex-cabinet ministers and former leadership contenders such as Ed Balls and Andy Burnham, are contesting the election.
Ed Miliband – whose brother David decided not put his name forward for election – is expected to wait until Friday to announce who will be given which roles.
Most speculation has surrounded the job of shadow chancellor, with both Mr Balls and his wife Yvette Cooper – leading figures in the last Labour government – seen as strong candidates.
Whoever is given the plum job will lead the opposition’s response to the government’s spending review in two weeks’ time.
Harriet Harman, elected deputy party leader in 2007, is already in the shadow cabinet as is chief whip Rosie Winterton – who was elected unopposed to the position last week.
But 49 MPs are fighting for 19 other places in the first shadow cabinet elections since 1996.
Under rules agreed by Labour MPs last month, at least six places must go to both women and men. Labour’s 258 MPs can vote for a maximum of 19 candidates but must vote for a minimum of 12 people for their ballot to be valid.
The 19 candidates with the most votes will be elected.
Former cabinet ministers Alistair Darling, Jack Straw and Bob Ainsworth are stepping down from the front bench and not contesting the elections.
Lord Adonis and Lord Mandelson resigned in the wake of Labour’s election defeat and former Foreign Secretary David Miliband is also returning to the back benches, having lost the party leadership to his brother.
The departure of these big names means several top jobs are up for grabs, and a mixture of senior figures and backbench MPs have entered the ballot.
Aside from former Education Secretary Mr Balls and former Health Secretary Mr Burnham, ex-Home Secretary Alan Johnson is in contention as are other former cabinet ministers Ben Bradshaw, John Denham, Douglas Alexander, Hilary Benn, Peter Hain and Shaun Woodward.
Aside from Ms Cooper, former Europe minister Caroline Flint, former Culture Secretary Tessa Jowell and former leadership contender Diane Abbott are among the 15 women standing.
Mr Balls, who was Gordon Brown’s adviser at the Treasury when he was chancellor, is known to be interested in the role of shadow chancellor but Ms Cooper – a former Chief Secretary to the Treasury – has also been suggested as a candidate.
And there has been speculation Ms Harman may be offered an additional role following her stint as acting leader.
Earlier this month, party members rejected a move to allow the party leader to choose who serves on the shadow cabinet when Labour is in opposition, but elections were limited to every two years as opposed to every year before 1997.
The chief whip is elected separately but Mr Miliband effectively got his choice – Ms Winterton – last week when he asked the incumbent, Nick Brown, to step aside.
The chairman of the Parliamentary Labour Party, its leader in the House of Lords and its chief whip in the Upper House also sit in the shadow cabinet.
Here is the full list of MPs standing for election to the shadow cabinet:
Diane Abbott
Douglas Alexander
Ed Balls
Hilary Benn
Roberta Blackman-Woods
Ben Bradshaw
Kevin Brennan
Chris Bryant
Andy Burnham
Liam Byrne
Vernon Coaker
Yvette Cooper
Mary Creagh
Wayne David
John Denham
Angela Eagle
Maria Eagle
Rob Flello
Caroline Flint
Mike Gapes
Barry Gardiner
Helen Goodman
Peter Hain
David Hanson
Tom Harris
John Healey
Meg Hillier
Huw Irranca-Davies
Kevan Jones
Alan Johnson
Tessa Jowell
Eric Joyce
Barbara Keeley
Sadiq Khan
David Lammy
Chris Leslie
Ivan Lewis
Ian Lucas
Fiona Mactaggart
Pat McFadden
Ann McKechin
Alun Michael
Jim Murphy
Gareth Thomas
Emily Thornberry
Stephen Timms
Stephen Twigg
Shaun Woodward
Iain Wright
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