Supporters of mesothelioma victims have launched a campaign to include an amendment to the draft Compensation Bill that would overturn this week's controversial House of Lords ruling.

In Barker v Corus UK, the Law Lords ruled that where a number of employers wrongfully exposed a claimant to asbestos fibres, each employer is only liable for a share based on the period of employment. Previously, the claimant could claim full compensation from a single employer.

The case is viewed as a massive victory for insurers. Claimant lawyers said insurers could save millions of pounds through smaller pay-outs to victims, although insurers played down the impact.

This week, Stephen Hepburn, MP for Jarrow, put down an early day motion, arguing that the ruling deprives asbestos-related cancer victims of their "rightful compensation".

He is calling for the government to introduce early legislation "to ensure victims are adequately compensated without being dragged through the courts by multinational insurance companies".

Law firm Thompsons has produced a draft wording to amend the Compensation Bill. Partner Ian McFall called for lobbying from MPs, trade unions and asbestos groups.

Meanwhile, Daniel Easton, asbestos solicitor for Leigh Day, said: "Insurers should be aware the Barker decision will mean higher costs. Claimant lawyers will need to do more work to trace employers. Insurers' own lawyers will also probably charge more."