Almost 27,000 low-paid workers in schools, hospitals and services for the disabled are taking to the streets today to protest at a public sector wage freeze.

Some 2700 orderlies, cleaners, kitchen and security staff at public hospitals will strike from 11am to 3pm to attend 27 lunchtime rallies from Kaitaia to Invercargill, and 3000 staff of the intellectual disability service IHC will strike from 11.30am to 8.30pm.

Another 21,000 school support workers, including teacher aides, librarians, science technicians and office staff are staging school-based protests today and plan their own march up Queen St at 12.30pm tomorrow.

All have been caught by the Government's Budget decision not to fund any new pay rises in the public sector this financial year because of escalating public debt.

District health boards and IHC said they both had contingency plans to cover the strikes and expected only "minimal" disruption.

IHC chief executive Ralph Jones backed his striking staff, saying his agency's 1.2 per cent funding increase from the Government this year was not enough.

"This is insufficient to cover proposed increases to ACC levies, let alone the rise in other costs such as KiwiSaver, electricity and food," he said. "Despite IHC working with the Service and Food Workers Union to underline the low wage rates of workers relative to other similar sectors, successive Governments have failed to address the issue."

Low-end wage rates have been plagued by anomalies since nurses in public hospitals won big pay increases in 2005, lifting them well above nurses and caregivers in private hospitals and rest homes and other staff in public hospitals.

The Labour Government earmarked funds to raise the starting rate for the other staff in public hospitals to $14.62 an hour, school cleaners gained similar increases last year, and caregivers' rates have also increased steeply in private hospitals. But the NZ Educational Institute, representing 13,000 of the 21,000 school support workers, said many of its members were still on starting rates as low as $12.94 an hour, only just above the minimum wage of $12.50.

The institute's support staff negotiations leader, Gaye Parlane, said her members deserved at least the $14.62 an hour that workers in other sectors had gained.

"Some of our support staff work with the most vulnerable children in the school [during the day], and then, to complement what they are being paid, they do the cleaning in the school at night, so they have this difference in their wage," she said.

She said the institute had met the Education Ministry about 10 times since it first lodged its pay claim a year ago, but were still being told there was no money available. The ministry declined to comment yesterday.

Meanwhile, Service and Food Workers Union secretary John Ryall said his public hospital members, already on $14.62, wanted a further 3 per cent rise in line with the district health boards' 3.1 per cent funding increase in the Budget.

"There is a massive discrepancy in pay between people on $150,000 to $200,000 a year and those people who are on between $12.55 and $14.62 an hour," he said.

"The people earning $12.55 are on the bones of their bums and they are struggling to actually survive from week to week. They need extra money now."

But district health boards spokeswoman Karen Roach said the 3.1 per cent funding increase was needed to cover the ongoing costs of the last increase in pay scales, as workers moved up the scales with length of service.

Unite Union secretary Matt McCarten said his members in low-paid private sector jobs supported the public sector rallies but could not take time off work under industrial laws.

He said his union had gathered 50,000 signatures so far on a petition for a citizen-initiated referendum to raise the minimum wage to $15 an hour. It needs more than 300,000 signatures by next May to force a referendum.