Five unions representing workers at the plants — which employ about 700 people — yesterday made a united appeal for a resolution of the issue.

Australian Manufacturing Workers Union North East organiser David Corben said staff were frustrated and concerned, wondering what’s going on.

“But we don’t know — we’ve tried a few different ways to find out,” he said.

Thales Australia has operated both sites under contracts from the government since the mid-1990s but these run to June 30, next year.

The Defence Department was contacted for comment yesterday, with a spokeswoman undertaking to finding out the status of the contract process.

Defence began a process in 2010 to decide what company or consortium should manufacture munitions when the Strategic Agreement for Munitions Supply expires.

This month’s budget papers said merely Defence was “progressing” new arrangements.

The union statement said: “Significant delays with this tender process occurred during the period of the previous Labor government and the process was further delayed in January this year when the Coalition government suspended this tender process.

“Since the tender process was suspended, Thales Benalla and Mulwala employees have heard nothing from the government concerning the future of both sites after the existing contracts end.”

Also involved are the Electrical Trade Union, the Australian Workers Union, the National Union of Workers and Professionals Australia.

Mr Corben said the unions first became aware of a “glitch” over the process just before Christmas.

“There’s been a hell of a lot of investment by the three companies to get their bids in, and then all of a sudden it’s stopped,” he said.

“When it did stop, Thales was pretty up front with us and said the process for whatever reason had stopped.”

The unions said the government needed to make a “strong, long-term commitment” to manufacturing munitions in Australia “very soon” if Mulwala and Benalla were going to be able to undertake significant manufacturing after mid-next year.

“In the last decade, based on a Howard government decision, over $300 million of taxpayer money has been spent on the redevelopment of the Mulwala site,” they said.

“This expenditure could be wasted if the right decision is not made soon concerning the long-term operation of both sites.”

Mr Corben said workers simply did not know if there was going to be any work come July next year.

“That’s huge (though) we’ve got some indication that things are probably going to be OK,” he said.

“We’ve been told that if the deal isn’t done by August-September no matter what happens there will be a disruption in business.”