Coalition vote slumps in latest Newspoll

The federal government has taken another hit in the latest Newspoll with its primary vote falling to below 40 per cent for the first time since the budget.

Australian Prime Minister Tony Abbott coughs during a press conference after an announcement in Geelong, Thursday, Aug. 6. (AAP) Source: AAP

Support for the federal government has dipped to a five month low, with Labor widening its lead over the Coalition.

The latest Newspoll conducted by The Australian and published on Monday shows the ALP leading the Coalition 54 per cent to 46 per cent, with their primary votes now locked at 39 per cent each.

Tony Abbott has lost his lead as preferred prime minister, with he and Bill Shorten locked at 38 per cent each.

Labor frontbencher Mark Dreyfus said the poll reflected dissatisfaction with former Speaker Bronwyn Bishop over the travel entitlements scandal.

It also showed voter anger over how Mr Abbott "chose to defend the indefensible" for three weeks, Mr Dreyfus said.

"(Mr Abbott) couldn't quite bring himself to accept that she had done the wrong thing," he told ABC radio.