It could be the political headache which never goes away.

On Tuesday, volunteer firefighters dumped a Supreme Court battle against Daniel Andrews' controversial industrial deal with the firefighters' union, claiming the agreement breached the CFA Act by undermining the role of volunteers.

After months of intense political pressure, the decision came as a welcome relief for the government. But the respite could prove temporary, with a fresh legal battle now brewing.

This time the challenge will come not from volunteers, but from the United Firefighters Union.