Queensland's opposition leader is under pressure to provide evidence after she claimed the highest levels of the Labor government were tolerating corruption and crime.
Deb Frecklington has written an opinion piece for The Courier-Mail, claiming the government is pocketing donations from the lawless CFMEU, and that the union is getting "unfettered access to the Palaszczuk government" in return.
"In this state, corruption and criminality are tolerated at the highest levels of government," she wrote.
"Not only does our government turn a blind eye to corruption, it even accepts huge sums of money from an organisation that extorts cash from Queenslanders."
Queensland's Council for Civil Liberties has called on the Liberal National Party leader to release evidence to back up her claims, and refer the matter to the Crime and Corruption Commission.
"Apart from assertions that 'the CFMEU is a rogue organisation and should be cut loose from Labor', Ms Frecklington offers up little or no factual basis for her high-level corruption claims in today's newspaper," the council's vice president Terry O'Gorman said.
The newspaper featured a story about Ms Frecklington's claims on its front page and ran her column in its opinion pages.
In the column, she accused the CFMEU of a "shocking" level of criminality, citing a spate of recent fines after it lost 10 cases brought by the Australian Building and Construction Commission.
A government spokesman has also questioned why the LNP leader went to a newspaper rather than to the corruption watchdog.
"If Deb Frecklington is serious, she'd be writing to the Crime and Corruption Commission not to The Courier-Mail," he told AAP.
The government also said the CCC's Belcarra Report specifically considered the issue of union donations and found that a ban on donations was not justified.
Ms Frecklington says Labor has pocketed $598,000 from the union since 2014, accepts its help during campaigns, and "even puts the party's election candidates on its payroll".
AAP has sought comment from the CFMEU.