A predictable backlash is emerging from British trade unions and consumer watchdogs following confirmation that half of all calls to UK national rail inquiries will soon be handled from Mumbai and Bangalore under a new £100 million contract.

British critics warn that consumers calling what is believed to be the busiest telephone number in Britain, used by around 150,000 people every day, will receive inferior service as foreign call centre operators often struggle with pronunciation, geography and general knowledge of the rail network.

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The Association of Train Operating Companies (Atoc) has responded by explaining that BT and Ventura won the five-year contracts, starting in April, following an 'exhaustive' tendering process.

BT's calls will be answered by its partner ClientLogic at centres in Bangalore, Derby, Newcastle , while Ventura's calls will be answered in Mumbai and Dearne Valley, South Yorkshire.

Union officials predict this could mean future job losses for UK call centres.

Sally Bridge, national officer at the Communication Workers' Union, described the decision as 'bonkers' and commented: "A vast amount of taxpayers' money goes into this service yet we understand it was a stipulation of tendering for the project that some of the work had to be moved offshore."

The union has written to UK Transport Secretary Alistair Darling asking him to intervene. It also said it would be meeting ClientLogic to discuss the job implications.

"Call centre work is important in communities like Derby and Newcastle. We are concerned that this type of work is very complex and it requires a lot of understanding of the geography of the UK and the intricacies of the rail industry. A lot of experience has been built up by call handlers in this country, and I just don't see how that can be transferred to countries like India," said Bridge.

David Fleming, a national officer of the technical and skilled persons trade union Amicus, described the move as disastrous.

He said, "At a time when some firms are making business decisions to return to the UK, it is absurd to think that half of all rail inquiries will be handled better from thousands of miles away.

"This decision, on the back of the report by the National Audit Office that new trains were often less reliable, spells disaster for the British travelling public."

Gerry Doherty, general secretary of the Transport Salaried Staffs Association, added the news was not much of a thank you for UK workers.

He said, "We are not convinced by the argument that exporting these jobs is economic in the long term. Who is going to pick up the social costs of call centre workers in the UK when they lose their jobs?"

Members of the UK Rail Passengers Committee say they will closely monitor the quality of the service provided, but Atoc insists trials in India have proved the quality of service offered in the UK could be maintained.

In London the Director General of the British Chambers of Commerce, David Frost, has separately warned how a skills shortage in the UK means hundreds of thousands of more jobs risk being sub contracted to India and China.

Frost described the National Rail enquiries contract as the tip of the iceberg and said, "The emphasis is placed on the outsourcing of call centre jobs, but it is a lot deeper than that.

"Forty per cent of our member companies are suffering skills shortages in vocational area. If the skills are not in Britain, then companies will go to India and China.

"We need more graduates in areas such as engineering. We need skilled technicians. We need a government drive to attract people to more vocational courses.

"Educational establishments in India and China are turning out high quality individuals with real skills that business needs."

Frosts warnings have been echoed in India where a recent study by the National Association of Software and Services Companies has predicted that the UK's ageing population and low birth rate will lead to labour shortages by 2010.

The report says this could result in some 300,000 jobs moving overseas with immigration filling the remaining gap.