Troubled nuclear power group British Energy has taken legal action to prevent an investor derailing its rescue package.

British Energy (BE), whose largest nuclear power plant is in Hartlepool, said it was filing an injunction in the US against Polygon Investment Partners, which is trying to block the UK company's proposed restructuring deal.

BE has already warned it may wind itself up, with the loss of thousands of jobs, if the rescue plan is not approved.

BE said it had filed the injunction because it believed Polygon had given late and defective notice of an acquisition of 35 million of its shares in July.

But BE said that it had taken the action to prevent Polygon pushing through changes to its company rules, which it said could stop the rescue deal going ahead.

Polygon's proposed changes would prevent BE delisting from the stock market without shareholders' permission.

They would also prevent BE's board extending the time limit for agreeing the rescue package, which expires in late January but still needs European Commission approval.

The injunction, if granted, would force Polygon to withdraw its demand for a shareholder meeting to table the proposals.

Polygon and another BE institutional shareholder, Brandes Investment Partners, say the rescue deal would leave them and other investors with an inadequate stake in the company.

But BE said the package, which will leave shareholders owning only 2.5 per cent of its equity, is the best it can achieve.