As construction jobs tumble in the credit crisis, thousands of U.K. workers downed tools recently to protest the use of foreign crews on a $290-million refinery project on England’s east coast. Unofficial supportive action spread from the Lindsey refinery in North Killingholme to unrelated powerplants and even the Sellafield nuclear fuel facility.

Underlying the dispute at the oil refinery, owned by Total U.K. Ltd., are growing concerns that Europe’s free market is working against British workers’ interests. What triggered the unofficial Lindsey strike was December’s arrival of a Sicilian specialty firm on the refinery’s desulfurization project.

Main contractor Jacobs Engineering Group Inc., Pasadena, Calif., awarded the small contract to Irem S.p.A., Siracusa, in competition with five local bidders and one other foreign firm, says a Total official.

Without attempting to recruit in the U.K., Irem imported workers from Italy and Portugal, reportedly housing them in a floating hotel in nearby Grimsby. Across the country, 900 employees of contractors at Sellafield stopped work for a day in support of Lindsey workers. Hundreds more walked out of RWE npower’s $860-million gas-fired powerplant project in Nottinghamshire and elsewhere.

The strikes won moral support from the country’s largest trade union. "Employers are excluding U.K. workers from even applying for work," claims Derek Simpson, joint general secretary of the Unite union.

But Unite’s concerns spring more from how the European Court of Justice has been interpreting the European Union’s Posting Workers Directive, a cornerstone of the European Single Market. Simpson claims, by excluding national union-employer agreements from rights guaranteed by the directive to workers across the E.U., the court has created conditions for "social dumping."