About 400 cleaners who work for cleaning giant Consolidated Property Services - which provides cleaners for buildings including Freshwater Place, 101 Collins Street, the CBA building and Casseldon Place - began industrial action on Thursday after failing to reach an agreement with the company over better pay conditions.

United Voice Victorian branch Secretary Jess Walsh said the cleaners - whose profession ranks among the lowest-paid in Australia - have been denied a pay rise for two years.

"They've had 12 meetings with Consolidated to try and get an agreement for a pay rise, but that's been frozen for two year," Ms Walsh told Fairfax Media.

She said most cleaners earned between $20,000 to $25,000 per year, which was not enough to live on.

"The most they get is $24 an hour, and that's for night shift," she said.

The cleaners are also asking that Consolidated Property Services promise to avoid using subcontractors or exploiting international students by signing the "Clean Start" agreement.

Ms Walsh said one major cleaning company, Glad, had committed to a 3 per cent pay rise for the next four years and ending subcontracting of international students as a source of cut-rate cleaners.

"Today is just the start," she said. "This will continue until Consolidated treats cleaners with respect."

As well as stopping toilet cleaning and resupplying, the disgruntled cleaners have also vowed to stop emptying bins.