The British labour union Unite has reportedly thrown its weight behind the private equity firm RHJ yesterday in its bid to take over Opel/Vauxhall.

According to The Guardian newspaper, union officials fear that more of UK-based Vauxhall's 5,000 workers will lose their jobs under Magna ownership than if RHJ buys the business.

The Canadian company has also proposed closing the firm's final salary pension schemes to all workers in the UK and the rest of Europe, the Guardian report said.

The Unite union reportedly believes Magna plans significant capacity cuts at Vauxhall's Ellesmere Port plant, which it fears would cast doubt over the plant's long-term viability.

According to a Magna bid proposal leaked last month, the consortium is planning to cut more than 1,000 jobs at Ellesmere Port and Vauxhall's other UK plant at Luton.

GM is currently reviewing revised bids from both bidders.