Some of Britain's biggest power stations could be forced into unscheduled shutdowns if industrial action over sackings at the Lindsey oil refinery escalates.

Hundreds of contractors at Drax in West Yorkshire and E.ON UK’s plant at Ratcliffe-on-Soar in Nottinghamshire have walked out in sympathy after Total, owner of the Lindsey oil refinery, last night sacked 900 workers for staging a series of “illegal” strikes.

Officials said that the wildcat strikes have not affected power generation activities so far. But sources said there was a risk that if the strikes became official, other staff at heavily unionised plants would refuse to cross picket lines. It could lead to plants being closed or forced to operate at a reduced capacity.

A spokesman for Drax, Britain’s largest power station, where up to 200 contractors have not shown up for work today, declined to comment on the potential impact of escalating disruption.

The spokesman said that there was no dispute between its management and workers. At E.ON UK, 150 contractors have not turned up for work for the second day running.

A spokeswoman for RWE npower, where 360 contract workers at its Didcot A and Aberthaw power stations have also downed tools, said that disruption was unlikely.

“No RWE npower staff are involved and the situation is not affecting operations at the power stations.”

Scottish and Southern Energy’s Fiddlers Ferry power station and EDF Energy’s West Burton plant have also been affected.

Nearly 900 workers at the Lindsey oil refinery in Lincolnshire have been told that they have until Monday to reapply for their jobs.

Total confirmed late last night that it had sacked the workers after an "unofficial, illegal walkout" by about 1,200 contractors in protest at 51 redundancies, brought work on a desulphurisation unit to a halt.

Lindsey, one of Britain’s biggest oil refineries, was hit by mass industrial action in January over the use of foreign workers. Hundreds of construction staff walked out after the company brought in Italians and Portuguese to build a new unit rather than use local employees.

The most recent protest began when Shaw, a sub-contractor, notified staff of redundancies because work on the current phase of the building project was ending. Workers said that an agreement not to cut jobs had been broken. Total denies any knowledge of such an agreement and ordered them to return to work and end their “illegal” action immediately.

In a statement, Total said: "The main contract company, Jacobs, and Total have repeatedly sought to encourage the workforce to return to work so that proper negotiations can take place.

“This is in line with the union and industry agreed process that negotiations over illegal strikes cannot commence until the workforce has returned to work.

“It is frustrating and disappointing that these attempts have failed.”

The GMB union had asked Acas, the employment and conciliation service, to convene talks between the parties, but Total said that it would not take part in any discussions until the contractors had returned to work.

Unite said that it was “extremely concerned” about Total’s actions and was last night seeking talks with the group’s local management.

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