SYDNEY • The group responsible for Australia's top opinion poll and an industry body for market research will review their methods to uncover how pollsters came to predict wrongly a victory for the opposition in the general election, they said yesterday.

Saturday's win by Australia's Liberal-led conservative government defied years of unfavourable opinion polls and bruised a Labor opposition that had widely been expected to triumph.

The "miracle", as Prime Minister Scott Morrison described the victory, is the latest political event to confound media and forecasters, following the Brexit referendum and the 2016 United States election.

"We will be conducting a review of the election polls, and particularly the methodology and sampling practices undertaken, with a view to working out why did they all call it incorrectly," said Mr Craig Young, president of the Association of Market and Social Research Organisations.

Newspoll, the country's most widely watched opinion poll, is also reviewing its incorrect forecast for a narrow Labor win, said Mr David Briggs, managing director of YouGov Galaxy, which runs Newspoll's surveys.

Opinion polls have played a key role in recent politics, prompting parties to remove four incumbent Australian prime ministers in eight years.

Australia's conservative coalition is now poised to secure an outright majority, allowing Mr Morrison to further his legislative agenda without support from independents.

Mr Martin O'Shannessy, who ran Newspoll for a decade until 2016, attributed the problem mostly to the decline of the landline telephone. This has robbed researchers of their most powerful tool, the telephone book, just as automated calls and cheap online surveys took off, with the latter lacking the depth or statistical rigour of phone interviews, he said.

REUTERS