But the directorate has said this is standard consultation and not a reaction to the industrial relations woes and protracted lawsuits that have plagued current contractors for more than two years.

In 2015, cleaner's union United Voice called on the ACT Education Directorate to terminate the contracts of two companies it claimed had underpaid staff, exposed them to unsafe working conditions and pressured them into signing contracts they did not understand.

In April 2016, the Fair Work Commission struck out a bid by the companies to scrap three rolling "clean start" enterprise agreements, which had promised higher pay rates and better conditions for the city's government-contracted cleaners.

But in June, the directorate extended the contract of one of the companies, Phillips Cleaning Services, despite it being embroiled in Federal Court proceedings.

Although the company vehemently denied the claims of underpayment and mistreatment, Education Minister Shane Rattenbury asked his directorate to conduct its own inquiry, a process that was still ongoing when the directorate renewed the contract.

An ACT Education Directorate spokeswoman said the "technical requirements" of the contracts had been changed, including monitoring and auditing functions, as a result of the inquiry

She said with the current cleaning contract due to expire in June 2017, discussions are beginning early on how the $12 million contract will be carved up.

"The tender process, which is expected to commence in April 2017, will follow all guidelines and requirements as set out in the procurement guidelines," she said.

"All tenders will be subject to review and weighting against a set of evaluation criteria, this includes industrial relations and employment performance."

The current contract to clean ACT primary schools has been in place since 2011.

United Voice secretary Lyndal Ryan welcomed the consultation as a way of "closing any gaps" that could lead to the exploitation of cleaning staff.

However she said there were still problems with sham contracting, work load and late payments, which she believed could be solved with the "rigour" of the contracts.

"Sham contracting is the heart of them matter, the entity rotation from our perspective is aimed at tax avoidance and many of the matters are before the courts," Ms Ryan said.

"There are situations where employees have been suing their employers for two years."

Ms Ryan said many cleaners were convinced the only way to rid the sector of its problems was for cleaners to be directly employed by the ACT government.

"They see contracting out as the problem, they're treated different to every other worker in the school," Ms Ryan said.

News of the consultation came days after cleaners in Canberra's hospitals recently won a modest pay rise after having their pay frozen for five years.