Daniel Andrews' attempt to ram through a deal with the firefighters' union has been dealt a major blow, with Victoria's human rights watchdog identifying a litany of breaches of the state's anti-discrimination laws.

In another setback likely to further inflame internal tensions, Victoria's Equal Opportunity and Human Rights Commission has ruled that up to 12 clauses in Mr Andrews' union deal could be discriminatory towards women, parents, carers and people with disabilities.

In a 36-page judgement delivered at the request of the CFA, the commission said complying with Victoria's Equal Opportunity Act was all the more important "in light of the low participation by women in the CFA workforce".

"We have been instructed that only 2.9 per cent of operational staff ... are women," the report said.