State Opposition Leader Lawrence Springborg and deputy Brisbane mayor Adrian Schrinner, both of the LNP, have blasted the state Labor government over the matter's referral to the CCC, just 2½ weeks out from the council election.

The Local Government Association of Queensland has also weighed in, criticising leaks and CCC referrals aimed at damaging political opponents.

Central to the stoush were revelations Lord Mayor Graham Quirk's LNP administration sought to sell council land to party donor Tan Boon Seng without going to public tender, as was legally required.

The council sought an exemption from that requirement from Deputy Mayor and Local Government Minister Jackie Trad, which was ultimately rejected last Friday.

The matter has since been referred to the CCC.

Ms Trad said she "absolutely not" involved in referring the matter to the CCC and nor had she been in contact with Labor's council campaign about the issue.

"The matter is now being assessed by the appropriate authority and we'll allow them to do their assessment without political interference," she said.

That did not sit with Mr Springborg, who said the CCC referral and subsequent media attention was a continuation of Labor's 2012 state election strategy.

"Jackie Trad is the chief mudslinger for the Labor Party and it's what she does effectively," he said.

"It's a great pity they can't run the state as effectively as they can throw mud."

Mr Springborg said Labor's campaign against then-LNP leader Campbell Newman in 2012 "blew up in their face" and Queenslanders had taken a "dim view" of the tactic.

Mr Springborg said the Newman government, of which he was a cabinet minister, introduced higher thresholds of proof before matters could be referred to the CCC, "so you wouldn't get malicious allegations being brought to the CCC for the purpose of doing someone else damage".

"That's been removed by this government and now you can see why," he told Fairfax Media.

Cr Schrinner said the entire affair was a "political stitch-up by the Labor state government".

"The people of Brisbane can rightly ask why the state government sat on this for five months and then released it just on the eve of the election," he said.

"I smell a rat and I think the people of Brisbane would smell a rat if they looked into it as well."

Council chief executive Colin Jensen requested an exemption from the requirement to put the land's sale up for tender from the state government on August 19 last year.

Department of Infrastructure, Local Government and Planning director-general Frankie Carroll sought more information on January 15, including whether there were any conflicts of interest.

"I can confirm that no conflicts of interest or material personal interests were declared by the councillors considering the proposed sale," Mr Jensen wrote back on January 27.

There was no mention of Dr Tan's donations to the LNP.

Cr Schrinner refused to say on Thursday whether Dr Tan's LNP links were mentioned at the civic cabinet meeting at which the matter was discussed.

"Cabinet discussions are in-house and they're that way because the City of Brisbane Act makes them that way," he said.

The matter was made public on Tuesday, when the ABC published details of the deal and Fairfax Media revealed on Wednesday it had been referred to the CCC.

Cr Schrinner said people should have taken heed of the CCC's calls for candidates not to make politically motivated complaints to the corruption watchdog with a view of making them public.

"I am confident the CCC will come back quickly and say there is no case here and that everything has been done appropriately," he said.

When asked whether he thought it was appropriate the CCC referral had been made public, Labor lord mayoral candidate Rod Harding said: "The matter of the CCC is for the CCC."

Mr Harding was repeatedly asked whether his campaign had any contact with Ms Trad's office about the affair.

"I can't speak for other people in the party, I can only speak for myself," he said.

"I'm busy campaigning, I've got 16 days to go and I have had my discussions with the journalist from the ABC who was asking legitimate questions – as I'm asking – of Graham Quirk to answer about a deal that is a secret deal."

LGAQ chief executive Greg Hallam said the election was under threat of "being hijacked" by candidates who spread "lies and falsehoods" about their political opponents.

"Over the past few weeks, there have been some claims made in the context of the elections that are plainly aimed at damaging individual reputations and smearing councils," he said.

"We've had State MPs Rob Pyne using the cover of parliamentary privilege and Ian Rickuss using mass mailouts to trash the names of respected council figures and now we see leaks about Brisbane City Council decision being referred to the CCC.

"It's time to stop the rot and remember that a clean election campaign is the only good campaign in the minds of the community."