Labour pains nearly over: New leader announced today

The new leader will have to be one tough cookie. Photo / Mark Mitchell

Labour's new leader will be revealed at 2pm today in what is expected to be a tight result with the expected front runners Andrew Little and Grant Robertson nervous but apparently optimistic.

Voting closes at midday under Labour's leadership election rules and the contenders will gather together at Parliament to be told the outcome at 1.30pm before the results are released publicly.

Mr Little, Mr Robertson, David Parker and Nanaia Mahuta have campaigned for the job over the past month.

Andrew Little said he was nervous but confident. "I am nervous because with preferential voting you don't know how it's going to shape up. But I'm confident I've run a good campaign and the feedback has been positive."

Mr Robertson said he was also happy with his campaign. "I'm happy that I ran a strong campaign and optimistic I can win what will be a close contest."

Mr Parker said he was "trepidatious" and Ms Mahuta said she felt "fine."

Under Labour's rules for the election, the caucus vote is worth 40 per cent of the final result, the party members are also worth 40 per cent and the affiliated unions 20 per cent.

Labour uses a preferential voting system under which the last placed candidate is knocked out in each round and their second preference votes allocated to the others until one gets more than 50 per cent overall. Grant Robertson is expected to get significant caucus support while Little is expected to secure a significant majority in the union vote. However, nobody is sure how party members will vote.

The contest was triggered soon after the election by the resignation of David Cunliffe who had originally decided to re-contest the position himself.

However, he pulled out soon after saying he had accepted he was not the right person to unite the caucus as required. Instead he endorsed Andrew Little, who also subsequently secured endorsements from the EPMU and Dairy Workers' Union. Grant Roberson has run with Jacinda Ardern as his running mate for deputy and a swag of high profile endorsement from former MPs including Sir Michael Cullen as well as other well known people.

David Parker initially said he would not contest it and was elected as acting leader on that basis. However, he changed his mind and put his name in later. Nanaia Mahuta threw her name in at the last minute after Mr Cunliffe pulled out.