The BBC's Joshua Rozenberg on the High Court case

The sufferers' lawyer, Brian Langstaff QC, argued that the cases could not be brought earlier because they were not typical medical negligence cases.

He said this was because there was no immediate cause and effect between smoking and lung cancer.

Some of the eight had been smoking since the 1930s and it was impossible to say at what point tobacco caused them lung cancer, said Mr Langstaff.

It was argued that tobacco companies had known by 1957, after a Medical Research Council report, that tobacco caused cancer.

The British Medical Journal had published research the same year on tar content and health.

Mr Langstaff said Gallaher and Imperial Tobacco, which together own 80% of the tobacco market, could have reduced the tar level in cigarettes as a result.

He said gradually reducing tar levels from 30mgs to 10mgs would have acted as some protection against lung cancer.

However, the companies had refused to accept publicly that there was a link between lung cancer and tar levels until 1971, said Mr Langstaff.

He commented: "There has been a failure by both companies to accept the obvious."

Negligence

John Pickering explains the lung cancer sufferers' case

The eight people he is representing are asking for permission to continue their actions, even though they were filed "out of time".

They are among 52 lung cancer sufferers are suing the firms.

In personal injury cases claimants normally have three years to begin a legal action from the date they become ill, or at least from the date they are diagnosed with an illness which could have been caused by someone else.

Most of the cancer victims were diagnosed more than three years before the first writs were issued in 1996, some much earlier.

John Pickering, one of the lawyers representing the lung cancer sufferers, said the delay in taking action was because the case was very complex and expensive and because his clients had been more concerned with their health and worried about taking action against powerful multinationals.

"It is not simple litigation. It is not like a road traffic accident," he said.

A decision is not expected until after Christmas.

Lawyers argue reducing tar in cigarettes before 1971 could have saved lives

The BBC's legal correspondent Joshua Rozenberg says victory for some or all of the claimants at this stage will be a clear pointer towards success in the main claim, which is due to be heard in the year 2000.

Tobacco companies have been increasingly under threat from legal actions. In the US, a similar case has been going for several years and could lead to huge compensation, mounting up into billions of dollars.

The UK case, which is around four years behind the US case, is unlikely to reach similar figures if it is successful, but it is probable that it will lead to a big settlement.

White Paper

The legal challenge comes as the Health Secretary Frank Dobson is about to unveil new proposals to cut smoking by children.

A White Paper, which will be presented to MPs in the next few days, claims cigarette companies are deliberately targeting youngsters.

Reports suggest ministers may bring forward by a year a ban on the use of billboards for tobacco advertising, and make nicotine gum and patches available on the NHS.