Workers in Scotland and Wales stage walkouts Press Association

A series of unofficial strikes broke out across Britain today over plans by a major oil company to give jobs to construction workers from Portugal and Italy. The contractors were to work on the giant £200m Lindsey oil refinery at North Killingholme, Lincolnshire.

Workers at refineries and power stations in various parts of the UK walked out, some holding placards quoting the words of Gordon Brown: "British jobs for British workers". The wildcat strikes mark the latest in a series of protests over the use of foreign rather than domestic labour by large companies in the UK.

More than 700 BP and INEOS workers at the Grangemouth oil refinery in Scotland walked out this morning after an 8am union meeting. Police were called to the Aberthaw power station, near Barry, South Wales, and 400 workers at a refinery in Wilton near Redcar, Teesside, have also downed tools.

Workers walked off the site at Total's Lindsey oil refinery on Wednesday, after weeks of discontent over the contract to build the plant's HDS-3 de-sulphurisation unit. The plant's owners put the contract out to tender with five UK firms and two European contractors bidding for the work.

The Italian company IREM won the contract and supplied its own permanent workforce, accommodating them in large, grey housing barges moored off Grimsby docks. It is understood 100 Italian and Portuguese workers are already on the site and 300 more are expected next month.

Asked about the refinery strikes at a news conference in Davos today, the prime minister said: "I understand people's worries about their jobs. I understand people's anxieties about employment across the country. But we are doing everything we can both to get economic growth moving in our country and to help people who are unemployed, to help them into new jobs."

Brown also stressed that protecting jobs was one of his key political aims. He said: "I came into politics to help people out of unemployment, to help people who were poor by building an economy that was confident and strong to weather this storm. I believe that the action we have taken to help people in work stay in work, to help people who lose their jobs get jobs again ... is the way to do it."

Protesters at the Lindsey refinery ended their action at around 10am, but vowed to be back on Monday morning.

Bobby Buirds, a regional officer for Unite in Scotland, said the workers at Grangemouth were striking to protect British jobs.

"The argument is not against foreign workers, it's against foreign companies discriminating against British labour," he said. "If the job of these mechanical contractors at INEOS finishes and they try and get jobs down south, the jobs are already occupied by foreign labour and their opportunities are decreasing. This is a fight for work. It is a fight for the right to work in our own country. It is not a racist argument at all."

Around 500 workers walked out at Scottish Power's Longannet power station, and just over 100 at its Cockenzie power station, while around 80 stopped work at British Energy's Torness facility.

In Lincolnshire, several hundred protesters gathered in a car park opposite the sprawling Lindsey refinery. Clutching placards and banners, two of which read "Right to Work UK Workers" and "In the wise words of Gordon Brown UK Jobs for British Workers", they listened as union leaders called on them to stand together in their protest.

Unite union regional officer Bernard McAuley addressed the men from a flat-bed truck. "There is sufficient unemployed skilled labour wanting the right to work on that site and they are demanding the right to work on that site. Our general secretary of Unite and the GMB have called upon the prime minister to call an urgent meeting with the heads of industry in the engineering and construction industry to clients and the trade unions to get round the table," he said.

"We want fairness. We want the rights of our members to have the opportunity to be employed, not just on this job but on all jobs around the United Kingdom."

In heated exchanges, some protesters called on their colleagues to march on Downing Street to protest at the situation. Shop steward Kenny Ward addressed the crowd and told them they had to stand together and take on the "greedy employer".

He said: "This is what it's about, it's about collective strength. I'm a victim, you are a victim, there are thousands in this country that are victims to this discrimination, this victimisation of the British worker."

He said colleagues across the country in Scotland and Wales were "standing shoulder to shoulder" with the protesters here.

Total issued a statement about the Lindsey strike this morning. It said: "We recognise the concerns of contractors but we want to stress that there will be no direct redundancies as a result of this contract being awarded to IREM and that all IREM staff will be paid the same as the existing contractors working on the project.

"It is important to note that we have been a major local employer for 40 years with 550 permanent staff employed at the refinery. There are also between 200 and 1,000 contractors working at the refinery, the vast majority of which work for UK companies employing local people.

"On this one specific occasion, IREM was selected, through a fair and competitive tender process, as the most appropriate company to complete this work. We will continue to put contracts out to tender in the future and we are confident we will award further contracts to UK companies."