As of midnight on Tuesday public servants at the Bureau of Meteorology will take rolling strike action at any time, moving into a new phase and ramping up pressure on the agency as negotiations stay deadlocked.

Bureau bosses rejected conciliation at the Fair Work Commission, but the industrial umpire on Monday scheduled another hearing for June 15 after a conference on Friday failed to end the dispute.

The main public sector union's deputy secretary Beth Vincent-Pietsch said the 1600-staff agency, whose workers have been without a pay rise for more than four years, remained a workplace in turmoil and a standout example of a broken industrial relations system.

"Enterprise bargaining across Commonwealth agencies has been difficult, but weather bureau bosses have taken it to a new low in their lack of respect for hardworking staff," she said.

The Community and Public Sector Union and Fair Work had urged the bureau to accept conciliation, but it had ignored this, Ms Vincent-Pietsch said.

"This matter should have gone to conciliation months if not years ago, rather than allowing weather bureau bosses to continue trying to railroad through a dodgy agreement.

"BOM bosses are still pushing a punitive agreement that targets many of its harshest cuts at frontline staff working shifts and in remote locations, showing their agenda threatens to undermine the bureau's fundamental purpose."

Union members at the Bureau of Meteorology in November began rolling strikes at times they judged would cause the most disruption to management.

Another round of industrial action started in late February. Staff will be able now to take blocks of strike action at any time of the day or night, on top of existing work bans, in a new phase to continue until at least April 9.

"Weather bureau staff are as determined as ever to get a fair agreement, whatever it takes, and they're angrier than ever at the ongoing attacks on their livelihoods and their important work," Ms Vincent-Pietsch said.

"CPSU members are just warming up in this round of industrial action and are prepared to take things even further if that's what's needed to get a decent resolution."

A bureau spokesman said it was negotiating in good faith with staff and unions, and that it wanted an enterprise agreement acceptable to staff and that was consistent with the Coalition government's workplace bargaining policy.

"The bureau is committed to reaching agreement with staff and their elected workplace representatives as soon as possible," he said.

The agency has used consultants to ask its public servants why they rejected a new workplace deal, after three "no" votes.

Despite the rejections, the bureau asked an "independent facilitator" to meet workers and ask for their views - even though the CPSU said bureau workers and the union had been clear with bosses about what needed to change for the dispute to end.

A decisive 60 per cent "no" vote in December killed the agreement offered to staff, who went into their fourth Christmas without a pay rise after years of negotiations.

The result followed a resounding 69 per cent "no" in February 2016 and a 58 per cent rejection of an offer in May. Shift work and remote allowances have been among sticking points in bargaining.

The Bureau of Meteorology is one of the last agencies still locked in industrial fights over new workplace deals, along with the Department of Home Affairs.