Australia's Liberal-National Coalition, the country's main opposition, reunited on Sunday, more than two weeks after the centre-right partners split in a row over hate speech laws.

"The Coalition is back together and looking to the future, not to the past," Liberal Party leader Sussan Ley said, appearing alongside National Party leader David Littleproud in Canberra.

The Coalition split on 22 January after the Nationals, citing free speech concerns, refused to back reforms moved by the government after two gunmen targeted a Jewish festival at Bondi Beach in December, killing 15 people.

"It's been disappointing, we've got to where we are but it was over a substantive issue," Littleproud said.

The Coalition suffered a heavy election loss last year and the split last month was the second in less than 12 months.

Last year's separation in May - largely over climate and energy policy - was resolved within a week.

This time the divisions were sown by hate speech reforms introduced by the centre-left Labor government after the Bondi Beach attack.

While the Liberals sided with the government, their National colleagues abstained from the vote in the lower house and voted against the measure in the senate, saying the measures had been rushed and posed a threat to free speech.

The legislation includes provisions that will ban groups deemed to spread hate and introduce tougher penalties for preachers who advocate violence.

Ley said the coalition had a responsibility to find a way back to government.

"I acknowledge this has been a difficult time. It has been a difficult time for millions of our Coalition supporters, and many other Australians who rely on our two great parties to provide scrutiny and leadership," she said.

The Liberal Party leader said both parties had struck an agreement that neither party could overturn decisions taken by the Coalition's joint "shadow cabinet".

Dating back to the 1940s, the Coalition had not split since 1987 before the brief separation last year.

The National Party mainly represents regional communities and often leans more conservative than the Liberals.

The Coalition is facing pressure from populist Senator Pauline Hanson's anti-immigration One Nation party, which has surged in polling, while the Liberal Party lost a swath of seats at last year's federal election.