The coalition's slide in the polls is continuing, with voters favouring Bill Shorten over Tony Abbott as preferred prime minister.

Labor leads the coalition on a two party-preferred basis, while the opposition leader is seen as more trustworthy than Mr Abbott, the latest Fairfax-Nielsen poll shows.

The nationwide poll, published on Monday, has Labor well ahead of the coalition, 54 per cent to 46 per cent on a two-party preferred basis.

That's the equivalent of a 7.5 per cent swing to Labor since September.

The report says Labor also leads the coalition by three percentage points on primary votes.

Mr Shorten continues to be out in front of Mr Abbott as preferred prime minister, 46 per cent to 41 per cent.

Mr Abbott's trustworthiness rating also lags behind Mr Shorten's at a record low of 35 per cent to 45 per cent.

The results follow the May budget, which proposed a $7 GP co-payment among other imposts.

Pollster John Stirton labelled the result as a bad one for the government and Mr Abbott.

"Mr Abbott fell behind in May 2014 after eight months in office, faster than any previous prime minister with the exception of Paul Keating who started out behind," Mr Stirton said.

"Julia Gillard was preferred PM for her first 13 months in office ... Kevin Rudd was never behind and John Howard was preferred PM for 21 months after being elected."

The survey of 1400 people was taken from Thursday to Saturday.