The FDA, in partnership with Prospect and PCS, has recently received judgment from the Court of Appeal in the case of Sparks and Others v Department for Transport (DfT).
The case was the DfT's legal bid to impose changes to its staff handbook, by reducing the amount of absences before triggering disciplinary proceedings.
Both the initial decision in the High Court, and the Court of Appeal, rejected DfT's argument that the trigger points were "inherently unsuitable for incorporation into contracts".
The court also considered that the specific number of trigger points within the handbook was contractual and could not be changed by way of an imposed policy.
FDA National Officer representing DfT, Martin Furlong, said: "This is about fairness and consistency across the department. This is an important victory for members in DfT, where the department was prepared to unilaterally make changes to employees' contracts.
"This should never have gone this far. Two separate courts have now upheld our challenge. The time has come for the department to discuss the underlying issues with the FDA and other staff unions.
"This has wider repercussions across departments that seek to impose policy changes that are in conflict with contractual entitlement."