Scott Morrison faces less friendly lower house in his first sitting week as PM

Scott Morrison's first week in parliament as prime minister is set to be no walk in the park, with the coalition losing its lower house majority.

Prime Minister Scott Morrison is heading into his first week in parliament with diminished numbers in the lower house. Source: AAP

After two weeks of preaching his values, Scott Morrison is set for a baptism of fire in his first week in parliament as prime minister.

The coalition will no longer have a majority in the lower house and Labor is due to make the most of the fact.

With Malcolm Turnbull out of parliament but not replaced, and Nationals MP Keith Hogan promising to move to the crossbench, the government's 76-seat majority is down to just 74.

Labor is on 69 seats, with Emma Husar back from leave after she was investigated for bullying her staff.

There are five crossbenchers.

The numbers mean Speaker Tony Smith may be required to vote with the government to break voting deadlocks.

Speaker Tony Smith may be called upon to break voting deadlocks, Source: AAP

Opposition spokesman Andrew Leigh says Labor will be using question time to ask why the Liberal Party felt the need to dump Mr Turnbull.

"We still haven't got a clear answer for that," he told ABC TV on Sunday.

He said Labor also won't let the government forget about their move to close the House of Representatives early at the end of last sitting fortnight, or that some ministers publicly backed Mr Turnbull before supporting his downfall.

Peter Dutton's au pair visa saga will once again be on the agenda when parliament resumes. Source: AAP

Home Affairs Minister Peter Dutton has said he's also prepared to defend his visa decisions in question time, as pressure grows over revelations he granted visas to European nannies in 2015.

Mr Morrison's deputy, Treasurer Josh Frydenberg, won't be by his side as the week gets underway.

Mr Frydenberg will miss his first parliamentary sitting day in the new role, as September 10 marks Rosh Hashanah on the Jewish calendar.

He and fellow Liberal MP Julian Leeser will be absent on Monday, along with Jewish Labor MPs Mark Dreyfus and Michael Danby.

In the Senate, the government has uncontroversial legislation it is trying to get through - such as aged care reforms - as it looks to minimise opportunities for Labor to cause problems.

In the lower house, changes to laws to stop victims of family violence being cross-examined in court by offenders will be debated.