Labor, which has governed Australia for only 38 of its 118 years as a federation, was rated an overwhelming favourite, both in opinion polls and with odds-makers, to topple the conservative Liberal-National coalition Government after its six years in power.
Instead, Morrison — who became Prime Minister only last August when a contentious internal party vote dumped Malcolm Turnbull as its leader — swept the Coalition to victory with what is likely to be an increased representation in Parliament.
The result is much the same as the last election, which delivered the Government a single-seat majority in 2016. Since then, public expectations have taken a roller coaster ride based on the media's reporting of polls.
Opinion polling has been a factor in conservative and Labor governments ousting four of their own prime ministers in the past decade, mostly recently elevating Morrison to Prime Minister.
Martin O'Shannessy, who headed the respected Newspoll market research company in Sydney for a decade until 2015, said he was "shocked" by the Government's victory, given the polling.
"It's not possible to tell exactly how the current polls are being conducted because they don't have the same method statement that polls in the past have had," O'Shannessy said.
Until Saturday, Newspoll had accurately predicted the winner of every Australian state and federal election since its inception in 1985. Australia has made voting compulsory, so pollsters' surveys of Australians' party preferences usually come close to the election result.
Newspolls are published every few weeks and are reported by the Australian media like a game score of the Government and Opposition's popularity and achievements.
Morrison's predecessor, Turnbull, justified overthrowing his predecessor, Tony Abbott, in 2015 on the basis of "30 losing Newspolls."
Turnbull's Administration had trailed Labor in more than 30 Newspolls before his Government replaced him with Morrison as elections loomed.
O'Shannessy said: "You should never sack the prime minister on the basis of a Newspoll — ever."
Labor MP Anthony Albanese, who was defeated by Shorten in a ballot of the party leadership in 2013 and will contest for the job again, said he had expected to be in government based on polling.
"The truth is that clearly there is a major gap between what the polling was showing and what the outcome was," Albanese said. "That is something that no doubt will be examined over coming days and weeks."
With just over 75 per cent of votes counted by last night, the Coalition had won 73 of the 76 seats needed to form a majority government, according to calculations from the Australian Broadcasting Corp.
With seven seats still undecided, the Coalition was expected to make further gains by the end of counting. The Government had gone into the election as a minority government, with just 73 seats.
Labor was holding 65 seats, with independents and minor parties claiming six.
The possibility remains that the Coalition will again have to govern in the minority, relying on agreements with independent and minor party MPs to transact government business.
- AP