Voting has closed in the race to be Labour's next deputy leader with the result to be announced at a special party conference on Sunday.
Labour's new deputy leader will be announced on 24 June
The six contenders were battling for support from Labour Party members, MPs and MEPs up until ballots closed.
Campaign team canvassing suggests the turnout could be in the 30%-50% range among Labour and union members.
Alan Johnson is favourite at the bookmakers but experts say the contest is difficult to call.
Much will rest on which candidate voters choose to name as their second preference, following a marathon seven-week campaign and more than a dozen public debates.
The votes - which include three million cast by trade union members - will be counted in a series of rounds.
Assuming no single candidate gains an overall majority of votes in the first round, the last place candidate will drop out.
At this point, the second choice vote of that candidate's backers will be allocated to the others - and the same process will be repeated until one of the contenders gets to the 50% mark.
The last of the hustings was a "virtual" one, screened on the Labour Party YouTube site on Thursday.
The candidates are International Development Secretary Hilary Benn, Labour chairwoman Hazel Blears, backbencher Jon Cruddas, Northern Ireland Secretary Peter Hain, Justice minister Harriet Harman and Education Secretary Alan Johnson.
Hilary Benn, who struggled to gain enough support from MPs to get on to the ballot paper, has traded places with Mr Johnson as the bookmakers' favourite.
The result of the contest, to succeed John Prescott as deputy party leader, will be announced at a special party conference in Manchester on Sunday afternoon.