Trade union leaders representing 15,000 workers at Jaguar and Land Rover are seeking urgent talks with management over the future of the two car brands.

The move comes as parent company Ford confirmed that it had appointed investment bankers to advise it on the future of two of Britain's best known names.

Concerns that Ford is looking to sell the Jaguar and Land Rover have led to calls for the government to intervene to safeguard their future.

Dave Osborne, national secretary for the automotive industry for the Unite union, said he was seeking urgent talks with management. "We have been pressing for assurances for the future from Jaguar/Land Rover and will redouble those demands now."

Ford, which lost $12.7bn (£6.4bn) last year, has been reviewing the future of a number of its global operations. That includes its premier automotive group which contains Jaguar, Land Rover, Volvo and, until earlier this year, Aston Martin, which was sold to a consortium of Middle Eastern investors.

Earlier this month there were reports, denied by Ford, that it was in talks with BMW over the future of Volvo and there has been persistent speculation that the two remaining British marques could be for sale.

Ford said today: "We are looking, with our financial advisers, to determine the best future for Jaguar/Land Rover."

Land Rover employs some 8,300 mainly at its Solihull and Gaydon faciltiies. Jaguar has a 7,300 workforce concentrated at Castle Bromwich, Whitley and Halewood on Merseyside where it shares production with Land Rover.

The close ties between the two marques would make it more likely they would have to be sold together but industry sources say there is much more interest in Land Rover, which had record sales in 2005 and 2006, than in Jaguar.

Several automotive manufacturers have already said they are not interested in buying the brands, leading to speculation they could be sold to private equity interests.

That drew immediate political protest. Labour MP John McDonnell said: "I am calling on the Government to intervene to prevent this sale which could result in huge job losses and the consequent impact on those local communities affected."

A spokesman for the prime minister, Tony Blair said: "We are in touch with the company. We still believe both Land Rover and Jaguar are highly successful companies and will have a highly successful future."