Mr Shearer has the su' />

David Shearer has twice as much public support than his rival David Cunliffe for the role of Labour's leader, a poll shows.

Mr Shearer has the support of 34.5 per cent of adult New Zealanders, compared with only 16.9 per cent for Mr Cunliffe, according to a Horizon Research poll for the National Business Review.

The Labour Party caucus is to elect a replacement for Phil Goff and his deputy Annette King on Tuesday, with the experienced former minister David Cunliffe up against one-term politician and former humanitarian worker David Shearer.

While both were seen to be of similar strengths in terms of leadership - 27.6 per cent saw Mr Shearer as a strong leader compared with Mr Cunliffe's 26 per cent - Mr Shearer is seen to better represent what people believe in (42.4 per cent to 28.3 per cent) and is much more inspiring than his counterpart (21.9 per cent to 11.4 per cent).

Mr Cunliffe is seen as more knowledgeable, with 37.1 per cent compared to 32.8 per cent, but Shearer is considered more trustworthy (27 per cent to 14.6 per cent), honest (22 per cent to 10.5 per cent) and moral (23.6 per cent to 11.4 per cent).

The most popular deputy leader is not even in the running.

Jacinda Ardern has the backing of 12.2 per cent, ahead of Shane Jones on 8 per cent, Nanaia Mahuta on 7.9 per cent and Grant Robertson on 4.4 per cent.

The poll surveyed 1356 people between December 5 and 8.