Unite leader Len McCluskey has threaten a "march of the workers" in protest at the loss of British jobs.
Speaking a the Labour party conference in Liverpool he pledged support to the 3,000 workers who lost their jobs this week at BAE Sytems.
He accused ministers of sacrificing jobs due to their obsession with austerity.
"This conference and our party today must pledge its support to fight back for those communites, to defend their livelihoods," he said.
McCluskey called on the government to intervene at BAE systems "to protect these jobs and these communities."
"The solution is in ministers' hands. The government must abandon its blinkered procurement policy.
"If they don't, UK taxpayers' money will be spent on American equipment instead of supporting UK jobs.
"They need to stop dithering on the contract for unmanned aerial vehicles and place it with the UK defence industry, including BAE Systems.
"Failure to take these decisions will mean that the critical mass, essential to our whole manufacturing future, is put at risk and we will enter another avoidable spiral of decline.
"Lets be clear - if the government is not serious about the march of the makers, then we will organise a march of the workers to focus their minds."
Have your say...
Please enter your comments below.