They haven't had a pay rise for four years, while watching Canberra's rates and rents skyrocket.

As well, the population of the building is now said to have risen to 10,000 when Parliament is sitting, but the cleaning workforce has been cut dramatically, putting a huge workload on the remaining, tired staff.

Luzia Borges thinks her 28 years' experience cleaning offices at Parliament House now counts for nothing.

"It's not fair to have no pay rise for four years because everything is going up, everything went up and we're still on the bottom of the pile," she told Fairfax Media.

"How are we going to live or save anything for when we retire?

"We are the lowest of the low, nobody cares for the cleaners, we're just here to do the job.

"We work hard and push ourselves to the limit, people are completely exhausted and you don't even get 'thank you'."

Her colleague, Anna Jancevski, is trying to save for her retirement.

"It's not fair that everybody else gets a wage increase but cleaners never do," she said.

The cleaners were frustrated that a recent strike during a sitting week made no difference to their case.

The cleaners' union, United Voice, says the wage freeze began when the Abbott government repealed the Commonwealth cleaning services guidelines as part of its war on red tape.

If the guidelines had been continued, there would have been annual wage increases for cleaners in Commonwealth buildings across Canberra, the union says.

Prime Minister Malcolm Turnbull was reporting last year as saying the hard-working cleaners "don't earn much money".

The union says he could demonstrate he understands the hardships faced by battlers, by reinstating the Commonwealth cleaning services guidelines.

The union's ACT branch organiser Erryn Cresshull said the cleaners at Parliament House had their last wage rise in 2012.

"Unfortunately they have not been able to achieve any wage increase since then," she said.

"It's a big pity because they do such an amazing job cleaning such a beautiful building and they work really hard.

"While their wages have remained frozen, all the prices have gone up.

"We say the government is to blame because the cleaning services guidelines were taken away as part of the red tape repeal and those guidelines would have ensured annual pay increases for the cleaners in Parliament House and other Commonwealth buildings."

Ms Cresshull said the government should review the disparity in the cleaners' wages.

"We'd like to ask the government to have a look at how much it has gained over the years," she said.

"There are now more people in Parliament House and more functions are held there, the cleaners are tired.

"We've been arguing with the contractor constantly for an increase in staff, unfortunately that hasn't happened, there's only about 40 cleaners here now.

"We're hoping if the contractor does get a tax cut [from the budget] then some of that will be passed on, either in wages to the cleaners or with extra staff, that would be a reasonable thing to do."

When Parliament House opened, more than 100 cleaners were employed keeping the building's 4700 rooms and other common spaces clean.

Limro Cleaning Services has a long-standing contract with the Department of Parliamentary Services, which runs Parliament House, to clean all areas of the nationally important building.

More than 80 public servants based at Parliament House will be moved to a nearby legal office for two years as the building struggles to deal with capacity and security upgrades.

Labor senator Penny Wong says many of the 10,000 politicians, staff, public servants, journalists and other workers at the building remain uncertain about future arrangements.