The lawyer behind failed legal action against the UK tobacco industry has hit out at health authorities for failing to support it.

Martyn Day of Leigh Day and Co Solicitors said it was a 'crying shame' that HAs had backed down after initial enthusiasm for the class action on behalf of a number of smokers.

Mr Day was giving evidence to the Commons health select committee's investigation into the tobacco industry and the health risks of smoking.

He had been gagged at an earlier hearing by a clause imposed by the tobacco industry when the court case collapsed last year.

This prevented him discussing any of the details of the case or becoming involved in any similar action. It was only after representations from the select committee that Imperial Tobacco agreed to release Mr Day from the clause so he could speak freely - for two and a half hours. After that he was 'back into purdah'.

'We talked to HAs before bringing action, ' Mr Day told the committee.

'The potential value of the case was£10bn in terms of compensation for the HAs.

'But the costs if they lost were£20m, ' Mr Day added. 'They clearly decided they could not take that risk.'

Mr Day said that in the US individual states had successfully taken action for damages against the cost of caring for people made ill by smoking. One recent settlement had been for $250bn.

But he said the Department of Health's legal opinion was that the NHS would not be able to claim for the costs of treating tobacco-related diseases because it was not charging for the service.

Mr Day's QC argued that this would not be a bar. The select committee has asked to see this argument. It could also ask to see an NHS Confederation document on 'the pros and cons of taking action against the tobacco industry'.

A copy of the document sent to H S J says a successful claim 'could produce a figure for the NHS in excess of£10bn' and 'it would be hard to imagine more of a nightmare scenario for the tobacco industry in the UK than being sued by all the HAs'.

But it also says the costs of any action 'may be prohibitive', that litigation would 'unequivocally' not produce immediate health gain and that difficult questions would be raised for the NHS about accepting 'dirty' tobacco money if it won.

The document also reiterates that the DoH 'has not been in support of litigation against the industry' and believes that it would be ultra vires for HAs to take action because of the charging question.

The idea of HAs taking action was enthusiastically endorsed at the NHS Confederation's annual conference in 1997, but had been abandoned by the following year.

Mr Day said the most useful thing the select committee could achieve with its inquiry would be to force the tobacco companies to release their files.

The committee asked if they could have access to the documents Mr Day gathered in his inquiries. These were under lock and key, he said, and he would have to see if they could be released, given the gagging agreement.