Turnbull must sack Brough over Slipper diaries, Shorten says

Opposition Leader Bill Shorten says Prime Minister Malcolm Turnbull needs to show some leadership and sack Mal Brough.

Mr Shorten arrived back in Australia last night having attended the Paris climate summit.

Labor has spent the past two weeks pursuing Mr Brough, the Special Minister of State, in parliament over claims he asked a former staffer to Peter Slipper to procure copies of the then-Speaker's diaries.

The minister said in a September 2014 television interview he had asked James Ashby to procure the diaries.

However, asked the same question in parliament on Wednesday Mr Brough denied this was the case.

Federal police have executed search warrants at Mr Brough's Queensland home as they investigate the matter.

"Malcolm Turnbull must be the only person in Australia who believes a word of what Mal Brough says," Mr Shorten said.

He said Mr Brough should never have been appointed to his ministerial role, which puts him in charge of government integrity.

"It's time for Malcolm Turnbull to show some leadership, admit he got this wrong and sack Mal Brough," Mr Shorten said.

The issue is set to be debated again on Thursday, the final day of parliament for the year.