Desmonds, who employ almost 2,000 people in the province, makes clothes for Marks and Spencer.

Clothes will no longer be made at its Springtown plant in Derry, with 170 factory workers and support staff losing their jobs.

Its Dungiven factory will close with the loss of 133 operative and support staff jobs.

Job losses on this scale reinforce the need for a coherent strategy to develop and defend a competitive hard core in our textile industry Mark Durkan SDLP leader and Foyle MLA

Both factories produce trousers and jeans.

A small number of jobs will also be lost at its factories in Irvinestown and at Newbuildings. Seventeen people will be kept on at Springtown as the firm is to maintain a cutting operation at the plant.

The company said in a statement that production at the two factories was no longer viable because of continuing pressures on profit margins.

It said it had "no alternative other than to restructure the business in order to match production capacity to market conditions".

It is believed the company plans to transfer some production to countries where labour costs are much lower.

Pressures

GMB union spokesman Alan Elliot said he was disappointed at the job losses but refused to criticise Desmonds.

"We were fearing the worst and our fears transpired."

Mr Elliot said the family-owned company had done "all in their power without assistance from government" to maintain jobs in Northern Ireland.

He said if Desmonds were a multi-national, it would have shut down operations in Northern Ireland years ago and moved its factories abroad.

He called on the government to help the remaining textiles manufacturers in the UK to retrain and re-tool so they can compete in fresh markets.

Mark Durkan, SDLP leader and Assembly member for the Foyle constituency in Derry, said it was "awful news for the workers and their families and a cruel blow to the local economy".

He said pressures and trends which had undermined textiles industry in Northern Ireland should be recognised, but negative developments could not be treated with mere resignation.

"Job losses on this scale reinforce the need for a coherent strategy to develop and defend a competitive hard core in our textile industry," said Mr Durkan.