Outgoing National leader Bill English is chairing his last caucus meeting before next week's vote on the leadership.
There are five lined up to try to replace him - Amy Adams, Steven Joyce, Simon Bridges, Mark Mitchell and Judith Collins.
The One News Colmar Brunton poll last night showed English has dropped to 20 percent as preferred Prime Minister - about three quarters of the 1000 respondents were polled prior to his announcement last Tuesday. And National had also dropped to 43 percent.
English has said he will not reveal his own choice but looks forward to others asking for his vote.