The longest and most bruising reform battle in the Andrews government’s 4½-year history ended on Thursday night when Labor's fire services reforms passed into law.

Labor needed the support of three of 11 crossbenchers in the upper house but had four, enabling the passage of legislation to overhaul the state's fire services after more than three years of bitter dispute.

The CFA will be devolved into a volunteer-only organisation under the Andrews government's fire reforms. Credit:Jessica Shapiro

As the division for the final vote was called, the government's leader in the upper house, Gavin Jennings, acknowledged that the bill "came with a lot of scar tissue and a lot of pain".

"I hope with the passing of this bill that scar tissue can heal," Mr Jennings said.