None of the major national pollsters accurately forecast the result, with all putting Labor in a winning position. Combined, Newspoll, Ipsos, Essential and Morgan had Labor 51.7 to 48.3 in front on a two-party preferred basis.

The pollsters' biggest misses were the Coalition's primary vote, which all underestimated by about 3 points, and the 2.9 per cent swing to the Liberal National Party of Queensland. Its commanding 57-43 per cent result compared to pollsters' predictions of 51-49.

Internal political party polling had pointed to the LNP doing well in Queensland but none had foreseen Labor's primary support dropping to just 27.4 per cent.

While missing the strong support for the Coalition in Queensland, pollsters also overestimated the strength of Labor in Victoria, where it took the state 52.3-47.7 per cent rather than a forecast 55-45.

YouGov Galaxy managing director David Briggs said it was the worst result by Australian pollsters on record.

"It's never happened in Australia. We've seen this go on in the US and Britain and other places but never here, until now," he said.

Mr Briggs said his company would be looking carefully at how it had missed the result, although he did not want to "fire from the hip".

He said the company's seat-by-seat polls, which had come in for criticism at past elections, had done comparatively well in the run-up to polling day.

Ipsos Australia director Jess Elgood said it would take some time for pollsters to work out what happened. She dismissed the "shy Tory" theory, which pollsters used as an explanation in Britain to explain John Major's surprise victory over Labour leader Neil Kinnock in 1992.

In the wake of Major's victory, British pollsters met to discuss what went wrong. Ms Elgood said that might be an option for Australian pollsters.

"We do check our data and we'll be looking at it again so see if we have missed something," she said.

Polling analyst Kevin Bonham said there had been signs of trouble through the campaign, with 16 consecutive polls putting Labor's two-party preferred result at between 51 and 52.

He said there had to be more transparency about pollsters' figures.

"The chances of this string of polls coming up with the same numbers is something like one in 100,000. There should have been some outliers," he said.

Mr Bonham rejected suggestions of a late swing to the Coalition, saying "it just didn't happen".

A senior Labor force said the published polling was not all that different to what it had internally, showing a solid result for Bill Shorten in Victoria and Western Australia.

It was also a bad result for betting agencies, all of which had the Labor Party at short odds to win.

A spokesman for Sportsbet, which paid out $1.3 million early to those who bet on Labor, admitted the company had lost at least $3 million with the Coalition victory.