Hundreds of demonstrators have protested outside an oil refinery against the use of foreign workers on a £200 million construction project.
Humberside Police said around 800 people took part in the demonstration outside the giant Lindsey Oil Refinery at North Killingholme, North Lincolnshire.
The action followed a walkout by hundreds of construction workers on Wednesday. The dispute centres on a decision to bring in hundreds of Italian and Portuguese contractors to work on a new £200 million plant on the site.
Protesters said the foreign workers will be housed on barges in docks off the nearby River Humber.
Unite union regional officer Bernard McAuley said workers at the refinery were joined by hundreds of trade unionists and other supporters from around the UK.
He said: "They've come from all over the country. We reckon there were almost 1,000 people here today. We've also had huge numbers of messages of support from people who are incensed by this decision. It's a total mockery."
Mr McAuley added: "There are men here whose fathers and uncles have worked at this refinery, built this refinery from scratch. It's outrageous."
Derek Simpson, joint leader of Unite, called for urgent meetings with the Government and employers to discuss the "exclusion" of UK workers from some of Britain's major engineering and construction projects.
He said: "It is outrageous that during a recession British workers are not even getting the chance to apply for well-paid work. The Government must intervene to level the playing field as a matter of urgency."
Superintendent Steve Graham, of Humberside Police, said the demonstration passed off peacefully and refinery owner Total said operations continued at the site despite the protest.
