"In the current climate, this is not surprising but we are extremely disappointed that Aston Martin have announced 600 job cuts," its national officer Dave Osborne said.
"This is devastating news for our members who have made major contributions to the Aston Martin brand. They now face a bleak Christmas.
"Unite will be working to maximise voluntary redundancies and we will vigorously oppose compulsory job cuts."
Aston Martin said it had been consulting with the trade unions.
"Like other premium car brands, Aston Martin has been forced to take action to respond to the unprecedented downturn in the global economy," chief executive Ulrich Bez said.
"These are regrettable but necessary measures in the extraordinary market conditions we all now face.
"Overall, we remain confident that the Aston Martin brand is the strongest it has ever been - with dedicated design, engineering and manufacturing facilities and an award-winning product range, we remain well positioned for the upturn in the economy."
Aston Martin sold 110 cars in the UK in October compared with 164 in the same month last year.
Sales last year were 7,300 but are expected to be 6,500 this year.
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