Inquiry into Qld govt amounts to nothing

The Palmer United Party's attempt to set up an inquiry to investigate the Queensland Liberal National government fell over at the 11th hour.

And it appeared on Tuesday it was concern for Labor's own that brought down the proposal.

PUP had wanted an upper house select committee to investigate the administration of the Newman government, the mining magnate's bete noire since he split with the LNP two years ago.

The opposition vowed to support the PUP motion and with the Greens on board, Clive Palmer's senators appeared to have the numbers.

But a Labor source said once the government moved an amendment to include the previous Labor government of Anna Bligh, that support was withdrawn.

The Greens were instrumental, voting with the coalition to include the Bligh government in the inquiry.

Government Senate leader Eric Abetz smiled with apparent surprise as he took the government's victory.

He had earlier pledged to delay the apparent Labor-Green-PUP deal by putting up a series of coalition speakers.

Government senators fiercely opposed the motion, saying it would likely be challenged in the High Court.

Attorney-General George Brandis described the move as a "gross abuse" of power and accused Mr Palmer of protecting his commercial interests.

The motion arose from Mr Palmer's "vendetta against the Queensland government", he said.

PUP could not be contacted for comment.