Rank and file sparks will stage a demonstration on Wednesday outside Balfour’s Blackfriars site.

The protest is set to be the first in a series of demonstrations as electricians fight plans by the industry’s eight largest employers to pull-out of the JIB pay and conditions agreements.

Around 400 sparks attended a meeting in London earlier this month and protest committees are being set-up across the country.

The electricians claim that the move to pull out of the JIB will “de-skill” the industry and see some sparks suffer pay cuts of up to 35%.

The big employers calling for change are Bailey Building Services, Balfour Beatty Engineering Services, T. Clarke, Crown House Technologies, Gratte Brothers., MJN Colston, SES and SPIE Matthew Hall.

A spokesman for the protesters said:  “The last time the electrical contractors attempted to cut wages by de-skilling the electrical trade in 1999 it provoked a series of coordinated strikes on the Jubilee Line, Royal Opera House, Pfizers and power generation projects across the UK.”