The Association of Market and Social Research Organisations launched the inquiry in June last year to determine what went wrong with polling predictions in the 2019 election.

The Coalition won the election with 51 per cent of the vote to Labor's 48 per cent, an outcome entirely opposite to what polls had predicted.

"Almost the mirror opposite of what the final polls found; all missing the result in the same direction and by a similar margin," the report said.

The report stated the first preference vote for Labor was overestimated because samples were "unrepresentative and inadequately adjusted".

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"The polls were likely to have been skewed towards the more politically engaged and better educated voters with this bias not corrected," inquiry chair Darren Pennay said.

"As a result, the polls overrepresented Labor voters."

Mr Pennay said participants had become increasingly disengaged with polling in recent years, with respondents less likely to answer the phone or participate if they did.

He said probability sampling, achieved by cold-calling participants, was the "gold standard" for pollsters to get a broad sample.

The news comes just a day after Hunter MP Joel Fitzgibbon urged his party to make a major shift on climate change and blue-collar voters as he quit shadow cabinet.

Western Sydney MP Ed Husic on Tuesday replaced Mr Fitzgibbon as the opposition's resources and agriculture spokesman after the stunning resignation.

Mr Fitzgibbon, a Labor right faction warrior, has been increasingly outspoken in a bruising battle over energy policy with senior figures from the party's left flank.

The party's most senior regional MP called for more support for resources sector jobs and warned against being too ambitious on emission reduction targets.