GlaxoSmithKline’s operations in Britain are likely to bear a hefty proportion of the planned staff cuts, with more than 1,000 positions in the country under threat.

GlaxoSmithKline (GSK) is the biggest employer in the British pharmaceutical industry, with 20,000 people in 23 sites across research, manufacturing, sales and administration.

As well as GSK’s global headquarters at Brentford, West London, the company has a string of medicine-manufacturing plants at Slough and Maidenhead, in Berkshire; Ware, in Hertfordshire; Dartford, Kent; Beckenham, Greater London; Crawley and Worthing in West Sussex; Barnard Castle, Co Durham; Ulverston, Cumbria; Montrose, Angus; and Irvine, Ayrshire.

Other research and administrative sites are located at Greenford, Harlow, Stevenage, Welwyn and Weybridge.

Although research scientists are believed to be safe, Glaxo’s British manufacturing operation is thought to be under particular threat because costs are far higher than in other Glaxo facilities overseas.

JP Garnier, the chief executive, has also made clear that outsourcing of manufacturing activities to Asia and Eastern Europe is a priority.

Some British plants could be closed down completely, while others are likely to be scaled down.

Further cuts are likely to be made in support, administration and finance roles.

Last night, British unions attacked the company’s plans, which come on the heels of a string of other UK job cuts and plant closures by the other leading drug groups AstraZeneca and Pfizer.

Linda McCulloch, Unite national officer for the pharmaceutical industry, described it as a “massive blow . . . The difference with GSK’s job cuts are that they are being made solely to keep shareholders happy. This is a profitable company that does not need to cut jobs or close plants and we fight any attempt by the company to do either in the UK.”

AstraZeneca said this year that it was cutting 15 per cent of its 66,000-strong workforce, including thousands of jobs in the UK. Pfizer said recently that it would close its drug manufacturing plant at Sandwich in Kent, with the loss of 420 jobs.

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