Federal Attorney-General George Brandis’ scathing assessment of the state Liberal National Party opposition as “mediocre” has received the backing of former Queensland premier Campbell Newman.

In a stunning rebuke to his former LNP colleagues in State Parliament, Mr Newman told Sky News on Monday night Senator Brandis was right to label the Queensland opposition as “very, very mediocre”.

Senator Brandis’ comments to Victorian Liberal Party president Michael Kroger were captured in an open microphone on Sunday, at the party’s annual meeting in Melbourne.

The Queensland senator also suggested the Palaszczuk government’s reintroduction of compulsory preferential voting in April could see the amalgamation of the Queensland Liberal and National parties reversed.

The candid nature of the comments suggested Senator Brandis was unaware the microphones were live.

“(Senator Brandis) made the point that the state Labor government is mediocre and also he made the comment about the state LNP and I’ve got to say that we’re not seeing performance from the government or, sadly, the opposition,” he said.

“…There’s the opportunity for (Opposition Leader) Tim Nicholls and the state opposition to really take it up to the government and actually to head off the Pauline Hanson threat.

“They need to stand up and start talking about the things that matter.”

But Mr Newman was less enthusiastic about Senator Brandis’ prediction that the LNP would de-amalgamate.

The Liberal Party merged with the Queensland Nationals in 2008 in a move that was largely prompted by the then-Beattie Labor government’s introduction of optional preferential voting.

“I don’t think that the solution is for the Liberal National Party in Queensland to be split apart,” Mr Newman said.

“It’s actually done a pretty good job since (former leader) Lawrence Springborg showed the leadership to bring it together and really what needs to happen is they need to start to fight, to be an effective opposition, to take the fight up to the government.

“That’s what Queenslanders want to see right now and, again, that would head off the challenge that we’ve been talking about for the last week from Pauline Hanson’s One Nation.

“But at the moment, she’s stealing their lunch and she’ll continue to do so until (the LNP) really get the runs on the board with ordinary men and women across this state.”

Mr Nicholls issued a statement on Monday afternoon saying he “strongly” disagreed with what Senator Brandis had said.

“I lead a strong and effective c opposition which is holding to account an incompetent, do-nothing government with no plans for Queensland,” he said.

“We recognise concerns from voters who do not believe they are being heard. That’s why my team is on the ground, listening to cers across the state.”