Mrs Willmore, who attended between 1972 and 1978, said workmen were still on site doing snagging work on the building as newly arrived pupils attended classes.

In July, High Court judge Mr Justice Nicol accepted that exposure to asbestos while at the school contributed to Mrs Willmore’s mesothelioma, a cancer of the lining of the lungs.

At the Court of Appeal, Knowsley Council’s barrister, Charles Feeney, said with 50,000 asbestos-related cancer cases expected over the next 40 years, uninsured local education authorities would be faced with a massive compensation bill if the appeal failed.

Mrs Willmore was well enough to give evidence at the July hearing, but so stricken by cancer she was unable to attend the appeal court on Tuesday.

Mr Feeney had argued the council had not breached its “duty” to Mrs Willmore.

He said there was no proof her condition was caused by asbestos at the school.

He also said councils are likely to face thousands of claims similar to Mrs Willmore’s over the next 40 years, but already find it impossible to obtain public liability insurance against asbestos-related risks.

Knowsley council has stressed its schools are “safe” and its safety procedures and asbestos management comply with strict legislation and guidelines.