About 400 workers at cleaning giant Consolidated Property Services took partial strike action on Thursday by refusing to perform a range of regular duties at dozens of office towers such as 101 Collins Street, Casselden Place, Freshwater Place, the CBA building and the NAB's Docklands building.

The office buildings are home to some of the city's biggest-name companies, including major banks, industry super funds, international law firms and several government agencies.

The cleaners had voted for the bans amid a long fight for a better pay deal.

The United Voice union, representing some of Australia's lowest-paid workers, said Consolidated's cleaning staff been denied a pay rise since 2012.

"The most they get is $24 an hour, and that's for night shift," union state secretary Jess Walsh said.

Consolidated is also being urged to promise to avoid using subcontractors or exploiting international students by signing the "Clean Start" agreement.

Krishna Ghimire, 26, has been working as a cleaner for a year while studying engineering at university.

He cleans offices at Southbank's Freshwater Place for four hours each night, but took part in a 20-minute stoppage on Thursday night.

"The main thing we are asking is for a fair workplace ... we need fair pay for our job we are doing here, and we need job security," he said.

"We love our job but a pay rise would really help us. We are not demanding such a higher pay rate and it is not something they cannot afford."

Consolidated Property Services did not respond to requests for comment.

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.