Nearly a quarter of the National Grid's 10,500-strong workforce started industrial action over pay at 6pm last night.
Members of Unite, Unison and Prospect unions voted against a two-year pay deal, which would have seen a 2.5 per cent wage increase backdated to July and a further 2.25 per cent hike this summer.
The 2,500 workers, who are largely in operational areas such as finance and gas distribution rather than engineering, have decided to work to rule and not accept overtime. This leaves the FTSE 100 giant, which delivers gas to 11 million homes and businesses in the UK, understaffed in what is typically the coldest month of the year.
Previously, National Grid had offered a 7.2 per cent increase over three years, but amended the terms following complaints from the unions.
They were concerned that this would tie down their staff to a deal until 2013.
A National Grid spokeswoman said: "We believe the revised offer – now a two-year deal rather than the original three-year deal – is a reasonable offer."Reuse content