More than $700 million will be set aside in next week's state budget as one state government plans for increased demand thanks to new, tougher bail laws.
The Victorian government passed laws earlier in May to make it harder for alleged offenders to be granted bail.
On Tuesday, the state government is expected to announce next week's budget will invest $727 million to ramp up capacity across the prison and justice system.
Almost 1000 additional adult prison beds will open across the system and an additional 88 beds will open at youth justice centres at Cherry Creek and Parkville.
The announcement also includes amendments to the Corrections Act to crack down on prisoners who assault and injure custodial staff.
The changes mean any prisoner convicted of assaulting and injuring staff can expect additional prison time on top of their existing sentence.
In a statement, a state government spokesperson said community safety came first in Victoria, and there are consequences for breaking the law.
"Our tough new bail laws mean more people charged with serious offenders are going to jail. That's why we need to open more prison beds now," the spokesperson said.
"We have zero tolerance for prisoners who assault our staff. Our new laws make the consequences clear."
Community and Public Sector Union secretary Karen Batt said despite more beds being brought online, there aren't enough staff to operate them, leading to concerns about safety and security.
The budget allocation of $700 million for prison beds is a positive step, she said, but more collaboration was needed with the government to ensure the funds are used effectively.
"This is the response we called for arising from the bail changes, but we also need to address continuing violence ... and the dismissive response from the Department of Justice hierarchy to these ongoing assaults inside to get existing officers confident to come back to work," Ms Batt told AAP.