A second major national opinion poll this month has measured a healthy lead for the Government, while the Opposition Leader's personal popularity appears to be dwindling.

Today's Newspoll in The Australian shows the Government leading 52 per cent to 48 on a two-party preferred basis, broadly in line with a Fairfax-Ipsos poll a week ago giving the Coalition a 53-47 lead.

Today's poll, which has a 3 per cent margin of error, puts the Coalition's primary vote at 45 per cent, 10 points ahead of Labor.

Malcolm Turnbull is preferred prime minister among 63 per cent of respondents compared to 17 per cent for Labor leader Bill Shorten — his worst result.

Labor frontbencher Jenny Macklin played down the importance of the latest figures, arguing the Opposition remained focused on laying out its policy agenda.

"People are crying out for more policy," she said.

The polling figures are the best for the Coalition in close to two years.

Mr Turnbull used the consistently poor results to justify his decision to oust Tony Abbott as prime minister.

Mr Turnbull gave a light-hearted response when asked about today's margin during a media event to announce the new chief scientist, Alan Finkel.

"I attribute improvement in the polls entirely to Minister Pyne's appointment of Alan Finkel," he said.

A by-election will be held in the safe Liberal seat of North Sydney in December to find a replacement for former Treasurer Joe Hockey.

New South Wales Liberal Party acting president Trent Zimmerman won pre-selection last night to contest Joe Hockey's former north Sydney seat.

It is expected the Government will easily retain the seat, but it will be the first ballot box test since the change of leadership.