More than 2,000 contract workers at energy facilities across the U.K downed tools Friday to participate in unofficial strike action over sweeping job cuts at French oil major Total SA's (TOT) Lindsey oil refinery.

Total's move to lay off 647 contract workers Friday at its Lindsey refinery in Lincolnshire, eastern England, was met with anger by unions and workers. The Unite union put the total job losses closer to 900.

Jacobs Engineering Group Inc. (JEC) informed workers by post of the cuts, telling workers to reapply for their jobs in the next four days. No-one was immediately available to comment at JEC.

The move follows a week-long dispute at the facility and unofficial strike action after 65 workers were told the hydro-sulfurization project they were working on was close to completion, putting their jobs in doubt.

Thousands of contractors, including welders, electricians and pipe-fitters across the U.K have joined the protest in support of workers at Lindsey.

The largest walkout Friday was seen at Royal Dutch Shell's (RDSB) Stanlow 240,000-barrels-a-day oil refinery where 450 contractors left the site, while three RWE AG (RWE.XE) power plants saw more than 400 walk out. At Ratcliffe power plant 150 left the site.

In addition a number of workers at British Energy's Hinkley Point B nuclear power station and Dragon Liquefied Natural Gas terminal in Wales joined the protests.

This is the third episode of rapid industrial action to hit the U.K.'s energy industry in five months, but the strikes have so far failed to affect output from plants, according to the companies that manage the installations. The speed of the action has been attributed to the increased use of mobile technology and social-networking sites to mobilize workers.

The U.K. government has waded in to the argument, taking a hard line against unofficial action, urging Lindsey workers to reapply for their jobs and start talks with bosses.

"The government's view is that unofficial strike action and demonstrations are never the right response to industrial relations problems," said a government spokesman at the U.K. prime minister's daily briefing.

The GMB union said it condemned Total's actions. "Total have for a full week refused to meet the union to resolve the problems through Advisory Conciliation and Arbitration Service," GMB general-secretary Paul Kenny said.

Discontent over the way the company has handled the negotiations could see the unofficial protests spread further, Kenny warned. "It seems pretty obvious that there is a mass case of victimization taking place here," he said.

The conciliation service has struggled to get all parties involved to sit down together at the negotiating table.

Total spokeswoman Emily Cooper said the company supports constructive negotiation between contract companies and their workforces under the national agreement between the construction industry and unions, but these talks "cannot take place whilst faced with an illegal dispute."

"We have had contact with ACAS today and hope to be able to talk with them further next week once our contractor workforce has had the opportunity to decide if they wish to continue on this important project," Cooper said.

-By Angela Henshall, Dow Jones Newswires; (4420) 7842 9285; angela.henshall@dowjones.com

(Selina Williams and Sherry Su contributed to this story.)