Overcrowding and privatisation of Western Australian jails is costing taxpayers money and endangering prison staff, according to unions.
About 50 protesters gathered outside the office of Corrective Services Minister Terry Redman in Perth, demanding an end to overcrowding and outsourcing of prison management.
Community and Public Sector Union WA secretary Toni Walkington told AAP the Liberal-National government had a "clear agenda to outsource public services", which was enriching multi-national firms to the detriment of prison services.
"This privatisation means we're compromising community safety, human rights, job security and standards of employment - just so these companies can make a profit," she said.
There is no accountability, no freedom of information access and while the government operates the service, "they've got no control", said Ms Walkington.
The $15 million fine imposed by the federal government on multi-national private security firm Serco last week, for poor management of immigration detention facilities, was a prime example of the private sector failing its duty of care.
WA Prison Officers' Union secretary John Welch said the government's "tough on crime" approach had also led to serious overcrowding which was endangering staff.
WA has the second-highest incarceration rate in Australia, behind the Northern Territory, and its prison population has jumped by about 700 to 4691 in the past three years.
"The prison system is designed for around 3500 prisoners - 13 out of the 14 prisons in the state are significantly or majorly overcrowded," he said.
The number of serious incidents reported in WA jails had gone up over the past 12 months as a "direct consequence of the overcrowding that has taken place over the past two years".
Opposition corrective services spokesman Fran Logan said the number of WA prisoners whose parole had been rejected over the past three years had leapt from 21 per cent to 79 per cent, resulting in 700 extra prisoners at a taxpayer cost of $43 million a year.
Corrective Services Minister Terry Redman rejected the notion WA was privatising prions.
"Claims that the state government is privatising the prison system are demonstrably wrong," he said in a statement.
"The role of the public sector in the prison system is actually increasing, with the new Eastern Goldfields and West Kimberley prisons to operated by the Department of Corrective Services."
Mr Redman also denied jails were overcrowded.
"The prison system is currently around 350 beds below capacity," he said.
"The state government's $655 million capital works program to repair years of neglect and mismanagement by the previous Labor government will increase prison capacity by more than 1500 beds."
