SUPPORT for Prime Minster Julia Gillard as preferred PM has jumped six points to 42% in the latest Newspoll, released on Tuesday.

The poll showed a reversal in support for preferred prime minister, with voter support for Tony Abbott falling from 40% to 38%.

Primary voter support for the Coalition fell three points in the past fortnight to 44%, while the Greens remained steady on 11%.

The Newspoll also showed growing voter support for former Prime Minister Kevin Rudd to return to the top job, with 47% of voters saying they would vote Labor if he led the party into the September election.

Mr Rudd remained preferred Labor leader over Ms Gillard, with 44% of voters supporting him, while only 25% of voters preferred Ms Gillard as leader.

The much-touted potential Labor leader, Workplace Relations Minister Bill Shorten, received 16% of support as Labor leader, putting him within nine percentage points of Ms Gillard in the Newspoll.

The Newspoll results come after Ms Gillard's trip to western Sydney and billion dollar promise to voters in that area to improve traffic congestion.

It also follows heated debate over the 457 visa program, with Ms Gillard promising to "put Australian jobs first".