CANBERRA - Support for federal Labor has hit a 15-year low as it tries to head off a business revolt over the carbon tax, the latest Nielsen opinion poll showed on Monday.

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The poll released by Sydney Morning Herald showed Labor government's primary vote has slumped two points to 31 percent, its lowest level in almost 15 years.

Primary support for the Coalition was 47 percent, a two-point rise, and its highest since February 2005. The Greens remained steady on 12 percent.

On a two-party preferred basis, the Coalition leads Labor by 56 percent to 44 percent.

In more bad news for Prime Minister Julia Gillard, the poll shows a majority of voters want her predecessor Kevin Rudd back in job.

Rudd, who was ousted by Gillard after climbing down over his emissions trading scheme, leads Gillard by 55 points to 38 in the preferred prime minister standings.

The poll involved 1,400 voters and was taken from Thursday evening to Saturday night last week.