Australian Prime Minister Scott Morrison has rejected calls for an early election despite the likelihood of his coalition government losing its majority after a weekend by-election.

Mr Morrison’s Liberal Party, the senior half of the ruling coalition, conceded defeat on Saturday in a by-election for the former seat of Malcolm Turnbull, who quit politics after being deposed as Liberal leader and prime minister in an internal party vote in August.

Early counting on Saturday showed a swing against the Liberals of more than 20%.

Postal votes counted on Sunday, however, showed the result might still be in doubt, tipping the balance back the way of Liberal candidate Dave Sharma.

Most analysts were still predicting victory for independent candidate Kerryn Phelps, although the official result might not be known for days.

Independent candidate Kerryn Phelps
Kerryn Phelps (Chris Pavlich/AAP Image via AP)

Losing Mr Turnbull’s old Wentworth electorate – for the first time in its 117-year history – would give the government only 75 of the 150 seats in Australia’s lower chamber, the House of Representatives, with one of their seats being held by the speaker.

The opposition Labour Party has 69 seats, while independents or minor parties hold six.

Addressing the prospect that his government would lose Wentworth, Mr Morrison rejected calls for an early election from the Labour Party.

He vowed to work with the independents and minor parties to ensure his government could still function.

“We have been at 75 (seats), not 76, since the former prime minister resigned,” Mr Morrison told reporters.

“In that time we had been able to legislate, run the parliament and we haven’t lost a single vote.”

Earlier, Labour’s manager of opposition business Tony Burke said that Mr Morrison should call an election before the next one is due in May, saying the coalition had said strongly in the Wentworth campaign that an independent victory would bring more uncertainty to Australia.

“I don’t see how he can argue that and then not say we have to have an election,” Mr Burke told reporters.

The likely result in Wentworth has been seen as a major backlash from the public against the government, after the country’s fourth change of prime minister in eight years via an internal party vote.

The likely winning candidate, Ms Phelps, said on Sunday she did not support an early election.

“All governments should go full term unless there are exceptional circumstances, and the next election is due in May next year and that’s time enough,” she told reporters.

Mr Morrison conceded the by-election showed voters were furious about Mr Turnbull being ousted.

“Liberal voters expressed their anger at the parliamentary Liberal Party … and we copped that fairly on the chin,” Mr Morrison said.

“The events of two months ago angered and outraged many Liberals and particularly those in the seat of Wentworth,” he said.