Many call centre jobs are based in deprived areas of the UK

The Communication Workers Union (CWU) described the proposals as "catastrophic" for the areas in the UK where call centres are based.

BT said no permanent employees would lose their jobs as a result of work being transferred to India.

The CWU said that as many as 200,000 UK call centre jobs could be lost across the industry over the next five to 10 years.

'Crude exploitation'

BT caused controversy earlier this year when it announced plans to create 2,200 customer service jobs in Bangalore, southern India in a bid to save money.

We will continue to protest and if necessary we will take strike action Mark Taggart, CWU

The CWU accused the telecoms company of paying Indian workers just 80p an hour, compared with �6 an hour for call centre workers in the UK.

Mark Taggart, an executive member of the CWU, told the union's annual conference in Bournemouth: "It is crude exploitation and it is simply about making more profits.

"Most companies are currently turning to India but it could soon be Malaysia or China.

"We will continue to protest and if necessary we will take strike action."

Disparity denied

Jeannie Drake, the union's deputy general secretary warned that if BT announced any further plans to move call centre jobs to India there would be a ballot for industrial action.

The union said it believed BT was bringing highly skilled technicians from India to work in the UK at some substantially lower rates of pay than comparable British workers.

BT said it was "simply not true" that Indian workers were being taken on at lower pay rates.

"The total package of Indian sub-contractors working on BT projects is comparable to those of their UK counterparts and is well above the UK national average wage. They do not lose out," a company spokesman said.

BT later issued a statement which said: "We are disappointed that the CWU continues to threaten industrial action on this issue, especially when less than 1% of the total number of people working in BT's call centres took part in demonstrations about India in March.

"Our plans for India are measured and responsible, designed to make BT more competitive and better able to serve our customers. This, in the long term, is critical to safeguard jobs in the UK."

Outsourcing customer service and IT maintenance work to Indian subcontractors is a growing trend in the UK, with many companies attracted by India's low labour costs and highly skilled workforce.