Hundreds of oil refinery workers demonstrated yesterday to demand 'British jobs for British workers' in a row over the influx of foreign labour.

Unions say up to 1,000 took part in the unofficial protest, accusing Italian and Portuguese workers of stealing their jobs.

They are furious that 400 are being brought in to work on a £300million construction project, claiming qualified locals are available to do the job at a time of soaring

Police were out in force at the Lindsey Oil Refinery at North Killingholme, North Lincolnshire, which was picketed by angry staff. Another mass protest is expected today.

The foreign workers, who are being housed in barges at Grimsby docks, have been hired to build a plant producing low-sulphur diesel.

The tender for the project was won by Italian firm IREM, which angered locals by bringing in the Europeans.

Union officials say they have been hired as a 'cheaper option' and reject claims that they are 'specialists'.

Under EU law the foreign workers are entitled to work and live here.

The protest began with a mass walkout on Wednesday. But the French-owned Total refinery insisted it managed to operate normally.

Cleethorpes MP Shona McIsaac said: 'It's a red rag to a bull for people who are out of work and have skills that could be used in this project.'

She said she wanted to ensure all workers had the 'same conditions'. Total insists that this is the case.

But critics say it is not clear whether the foreigners are being paid the same as Britons for similar jobs or if they are just 'cheap labour'.

Bernard McAulay, regional officer for the union Unite, said: 'There are thousands of skilled engineers unemployed in this country, yet they give this work to a company in Sicily.

'We have a lot of people quite capable of doing this work, yet when this country is losing thousands of jobs, the contract goes abroad.'

He said supporters had travelled from across Britain to demonstrate, adding: 'There were almost 1,000 here. People who are incensed by this decision. It's a total mockery.

'There are men here whose fathers worked at this refinery, built it from scratch. It's outrageous.'

Contractors at the nearby Conoco Phillips refinery joined the action.

Workers also walked out in sympathy at BP's Dimlington gas terminal in East Yorkshire, its chemical manufacturing plant in Saltend, Hull, the Staythorpe Power Station construction site in Nottinghamshire and Scottish Power's Longannet power station in Fife.

The 500-acre Lindsey refinery is the third largest in Britain, processing 10million tonnes of crude oil each year - 200,000 barrels a day.

Around 100 foreign workers are on site and 300 more are expected next month, staying here for up to a year.

Total said: 'We recognise the concerns but there will be no redundancies as a result of this contract.

'We are disappointed our contractors have taken this action.'