The latest Newspoll shows federal Labor's primary vote falling below 30 per cent for the first time in three months.

The poll, published in The Australian newspaper, shows the Government's primary vote has dropped three points to 28 per cent.

The Coalition's primary support was 46 per cent, down two points, while the Greens remained steady on 11 per cent.

Two-party preferred results were steady – the Coalition maintained its 56 per cent to 44 per cent lead over Labor.

Opposition Leader Tony Abbott gained one point as preferred prime minister, extending his lead to four percentage points over Prime Minister Julia Gillard.

Forty per cent of respondents said Mr Abbott was their preferred leader compared to 36 per cent for Ms Gillard.

The poll has a three per cent margin of error.