Victoria's rights commissioner will try on Thursday to challenge the controversial new workplace deal for Melbourne’s firefighters.

The Equal Opportunity and Human Rights Commission will appear in the Fair Work Commission to argue against the deal, which has been several years in the making but which Equal Opportunities Commissioner Kristen Hilton believes entrenches discrimination in the Metropolitan Fire Brigade.

Rights commissioner Kristen Hilton. Credit:Darrian Traynor

The deal has been agreed between the brigade and its firefighters, represented by the hardline United Firefighters Union, and now must be approved by the Fair Work Commission.