The coalition has consolidated its massive two-party lead over Labor, and would win an election held now with an eight per cent swing.
The latest Fairfax/Nielsen poll shows the stand against the carbon tax by Opposition Leader Tony Abbott, which came into force on Sunday, is resonating with voters.
The poll shows opposition to the tax has risen three points to 62 per cent, while support is down four points in a month, according to the poll of 1400 people taken from Thursday to Saturday.
It found that 51 per cent of people believe they will be worse off under the carbon tax, which is up one point from a month ago.
Amid controversies over the carbon tax and asylum seekers, the coalition has slightly widened its two-party lead to 58 per cent to 42 per cent.
Labor's primary vote is up two points, but is wallowing at 28 per cent, while the coalition's primary vote is steady on 48 per cent.
The approval rating for Prime Minister Julia Gillard eased one point to 35 per cent while Mr Abbott's approval is steady at 39 per cent.
Both leaders were in Melbourne on Sunday campaigning on the new tax.