Unite reports 70% of staff at six Jaguar Land Rover sites voted in favour of the proposals it - and the GMB - recommended.
In a joint statement, the unions said: "The choice for our members was clear - further mass redundancies or what is undoubtedly some short-term plan in order to secure the future for our members and their families."
Jaguar Land Rover staff face reduced working week and pay freeze to avoid redundancies
Jaguar Land Rover staff have voted to have their working week reduced to four days and have their pay frozen for one year as a means of avoiding redundancy.
