* UK union fears 1,000 plus job losses at Vauxhall plants
* Union seeks talks with prospective owner Magna
LONDON, Sept 22 (Reuters) - A union representing workers at GM's British Vauxhall unit said on Tuesday it feared that at least 1,000 jobs could be cut under a planned takeover.
The head of the Unite union called for talks with Canadian car parts company Magna over the future of the two British plants, at Luton, in southern England, and Ellesmere Port in the northwest, which employ more than 5,000 workers.
"For Britain, there is likely be 1,000 or more job losses almost immediately in both of our plants," Tony Woodley told BBC television.
"Worse than that, without the investment and with capacity being stolen from the plants to go elsewhere, there will be no long-term future for either of the British plants," he added.
Magna and Russian partner Sberbank have agreed to buy a majority stake in GM's European arm Opel. They plan to cut about 10,500 jobs from a workforce of 50,000, half of whom work in Germany.
Some countries that are home to Opel plants have urged the European Commission to ensure that the deal with Magna did not favour German workers because of 4.5 billion euros in promised aid from Germany.
"The political stitch-up with the German government means that in the longer term all the other countries are going to lose out," Woodley said.
(Reporting by Keith Weir and Rhys Jones; Editing by David Cowell)