BBC Health Correspondent Karen Allen: "That judgement will now be tested in the court of appeal"

East Kent Health Authority is appealing against a High Court ruling which said that the three were entitled to compensation.

Edward Faulks QC, representing the authority, said that the natural "limitations" of the screening programme meant that some cancers were always missed.

There are fears that the ruling may destroy the national screening programme because it sets standards of accuracy that are near impossible to achieve

Mr Faulks said the screeners who initially look at the smear tests want the public to know that "it is not infallible".

"In the light of the problems that have now arisen, the Department of Health is anxious to emphasise this," he added.

The health authority estimates an extra one million women a year nationwide would have to be called back for further tests - most of which would be unnecessary.

But the women's solicitor has said the appeal is a waste of NHS funds.

Mr Faulks told the Court of Appeal that national standards recommended that between 85 and 95% of women with cancerous or pre-cancerous cells should be detected.

He said: "There are always going to five percent false negatives. These errors are always detectable with hindsight and into which the tests being appealed did fall."

Women needed hysterectomies

The cancers were not spotted at Kent and Canterbury Hospital

Eight women died, 30 needed hysterectomies and more than 90,000 women had their tests re-examined after mistakes at the Kent and Canterbury Hospital between 1989 and 1995.

The authority has paid more than £1m to 47 women, but the three women were among 14 cases the authority had disputed.

Helen Palmer, Sandra Penney and Lesley Cannon, who won their case in February, said their lives were destroyed by the blunders.

They developed cervical cancer and had to have hysterectomies while they were in their 30s.

None of the three women will be giving evidence at the appeal, as they are all quite ill.

'No screening is perfect'

Figures from the Imperial Cancer Research Fund suggest the NHS Cervical Screening Programme prevents up to 3,900 cancers each year.

Doctors accept that no screening process is perfect and there will always be a margin of error - their task is to reduce that margin as much as is possible.

But the High Court ruling demands too high a level of accuracy given today's technology, the litigation authority says.

Lawyers for the health authority and the hospital argued at the High Court that the women's smears were borderline and that they were suffering from a very rare type of cancer. They said the screeners had made excusable errors in passing the slides.

The judge rejected this argument and said the screeners should have sent the samples for further tests.