Victoria's long-running and controversial battle over new pay deals for firefighters won't see volunteers drop out of the CFA, the state's emergency management boss says.
Emergency Management Commissioner Craig Lapsley says he's heard of a couple of CFA volunteers deciding to leave the fire service, but he didn't expect it to be common.
"I have not seen any evidence of the loss of volunteers," Mr Lapsley told an upper house hearing on Tuesday.
Under the proposed deal between the United Firefighters Union and the CFA, Mr Lapsley will oversee contentious areas to make sure both sides are being reasonable.
"I've been personally concerned that I've been asked to implement something that is a bit of a toothless tiger, (but) we've taken advice that that wouldn't be the case," he said.
Changes to the Fair Work Act passed federal parliament last week as the Turnbull government delivered on its election promise to intervene in the CFA dispute.
The union has reportedly decided to launch a High Court challenge against the new laws but did not return calls or emails to media outlets.
A state government spokesman has said the legislation is "totally unnecessary" as the proposed agreement has important protections for volunteers.
The CFA confirmed on Tuesday that interim chief executive Frances Diver would stay on until a new boss was employed, after reports emerged that she was moving overseas.
A CFA spokeswoman said the board was searching for a full-time chief executive but Ms Diver would remain until then.
Opposition emergency services spokesman Brad Battin said it was not ideal to bring in a new chief executive on the eve of the upcoming fire season.
The firefighting authority has also been ordered to hand over government documents it claimed were confidential to volunteers.
The Supreme Court ordered on Tuesday the CFA hand four documents to Volunteer Fire Brigades Victoria ahead of a trial over the lawfulness of the controversial pay deal.
