In a submission to the Carr review, a commission set up by the UK government in April to look at the laws governing industrial disputes, Ineos has proposed unlimited civil liability for damages resulting from "unlawful union actions that target individuals, suppliers and customers."

The company now headquartered in Switzerland is also urging the government of its former legal base to extend the legal notice for trade unions to declare industrial action from seven to 21 days.

This, Ineos argues, would limit the safety risks associated with unplanned shutdowns for large manufacturing plants such as its complex at Grangemouth, Scotland, site of a prolonged labor dispute last autumn.

"We cannot tolerate the thuggish intimidation of managers, suppliers and customers by out-of-control unions. Last year, one of UK's largest industrial sites nearly closed down because of reckless union actions," the company said.

The union Unite at the center of last autumn's dispute, called the Ineos intervention "unhelpful," in view of the need to rebuild good industrial relations at the facility that once belonged to BP and receives oil from North Sea fields.

"What Ineos is calling for is outside the scope and remit of the Carr review, which, in our view, was a political stunt set up at the time but from which the government has since rowed back," said a union spokesman.

Unite says it does not plan to participate in the review process, not least because it does not believe that Sir Bruce Carr, the man appointed to oversee it, is independent.

The British Trades Union Council, TUC, said the call for new measures was unnecessary, as the UK already has strict laws governing strikes and public order offenses.

"Rather than waste taxpayers' money on a needless review, time would be better spent investigating how blacklisting was used by bad employers for many years to silence the unions' voice," a TUC spokesperson told the Guardian newspaper.

The Liberal Democrats, part of the governing coalition with Prime Minister David Cameron's Conservatives, have distanced themselves from the Carr review, saying any inquiry should look at employer abuses such as blacklisting as well as malpractice by unions.

The Carr review was called by the government after claims by a senior manager at Ineos that a mob of protesters were sent to his home, leaving him fearing for his safety. These and other tactics were said to have been organized by a "leverage team" seen by critics to be trying to bring back the union militancy of the 1970s and 80s.