The group hopes to cut production of the Astra model at Ellesmere Port according to GM Europe chief Carl-Peter Forster.
He said GM was reviewing production capacity across its three Astra plants in Europe as it expects demand for the car to decline.
Unions are in talks with GM to spread the job cuts across Astra plants in Germany and Belgium, as well as in the UK.
GM stressed that no decision has yet been made.
Foster said: “We want to keep the UK and German plants because we want to be close to our customers, and those are our biggest markets. But we also want better productivity.”
The company is looking at ways of increasing production and cutting costs as part of a restructuring drive.