Strike action is to be stepped up as a pay row at a Birmingham factory escalates.

Unions at Concentric Pumps in Erdington are planning to down tools for two periods of seven days in a dispute centred on a 2.8 per cent offer.

Mr Mike Trelfa, GMB regional officer, said the unions GMB and Amicus would call two seven day strikes: the first starting on July 4 and the second on July 18.

They have already staged a series of one day strikes, with two more planned on Wednesday and Friday this week.

The unions claim about 180 members have been downing tools at the company.

Mr Trelfa says members had accepted changed shift patterns, top earners had lost up to £40 a week in bonuses, and staff had taken pay settlements below the rate of inflation over recent years. Company performance had improved and the 2.8 per cent offer was the straw that broke the camels back, he said

But management say no more cash is available. They believe that a share bonus scheme benefits employees by between two and three per cent in new money, on top of the 2.8 per cent rise.