The electricians believe Balfour is the driving force behind plans for eight leading M&E contractors to quit the industry’s JIB industrial relations agreement.

The Enquirer understands that protesters will step-up their campaign with Balfour Beatty as the main focus of demonstrations.

One ringleader said: “Balfour Beatty are the big one in all this – if we get at them then the others will melt away.”

The new strategy was outlined at a mass meeting in London on Tuesday night ahead of another round of site protests yesterday.

The Unite union is known to be backing the rank-and-file protests unofficially and the grass roots campaign has also forged links with the American Teamsters.

Unite is also coming under pressure to hold an industry-wide strike ballot over the row.

The rank-and-file movement is hoping to stage an all-out construction strike on November 30 to coincide with a national day of action by public sector workers.

The latest protest is set to take place today at the Sellafield power station site.

A statement from the HVCA trade body said: “These protests by a small minority make no sense at a time when British industry is looking to improve its skills base, develop its workforce and modernise its working practices.

“The Building Engineering Services National Agreement (BESNA) will make life simpler for staff and their employers by replacing the five separate arrangements that currently exist, while helping to make UK engineering more competitive.

“No employees will lose their jobs as a result of the changes the employers are proposing to make, nor will they have their wages cut, nor be downgraded through a process of de-skilling.

“The UK’s building engineering services sector employs more than 600,000 workers. Of the 6,500 individual workers across the country (i.e. just over one per cent of the total) who have been invited to accept the BESNA, electricians’ wages will remain the same, while plumbers and mechanical workers will receive pay increases. All pensions, sick pay, insurance and other welfare benefits will be unaffected.

“As well as getting their facts wrong about the terms of the agreement, the activists who are organising the protests have not been asked to sign the new contracts, as they, and others who have joined in on the protests, are employed under quite different terms and conditions.

“We remain both keen and hopeful that the Unite trade union will accept our invitation to resume discussions about the proposed new agreement.”