Thousands of women with family histories of breast and ovarian cancer could pay higher insurance premiums or even be denied cover altogether under new proposals from the insurance industry.

The Association of British Insurers (ABI) is expected to lodge an application for permission for its members to ask women whether they have been tested for the BRCA1 and BRCA2 mutations.

The faulty BRCA genes are responsible for about five per cent of the 41,700 new cases of breast cancer and 10 per cent of ovarian cancers diagnosed in Britain each year.

If the insurers are granted permission by the Genetics and Insurance Committee (the organisation that advises the Government on the issue), women who have tested positive could be forced to pay higher premiums. Some companies may even refuse high value life or critical illness insurance.

A notice published on the GIC's website said, 'The Committee expects that the Association of British Insurers will submit in late 2006/2007 four revised and updated applications for the use of adverse results from predictive genetic tests of the BRCA1 and BRCA2 genes (breast/ovarian cancer) in helping to determine insurance premiums for life and critical illness insurance.'

At present, the only predictive genetic test the committee has allowed insurance companies to ask about is for Huntington's Disease. This is because of the lack of environmental influences on its development.

However, across Europe, several countries have banned insurers from using genetic tests to decide premiums. Also, in 2005, a voluntary agreement to avoid using such tests by British insurance companies was extended until 2011.

Under this agreement, insurers can ask potential customers only about genetic testing results for Huntington's Disease. However, they can only ask for the information for policies that are worth more than '500,000 for life insurance, more than '300,000 for critical illness and more than '30,000 a year for payment protection.

But the association's genetics working party has indicated that it would like to bring about a change seeking permission to ask about two cancer genes and wants approval by the end of the year.

Approximately one in 850 women in Britain inherits a faulty BRCA1 gene. Those women will have a 14 to 18 per cent chance of developing breast cancer at some point in their lives.

Meanwhile insurers are not allowed to ask prospective policyholders if they have HIV, but they can ask them if they have exposed themselves to the risk of infection through unsafe sex or sharing needles.

An alliance of 45 leading charities, unions, scientists and lawyers have called on the Government to ban this genetic discrimination.

A study carried out by the charity Breakthrough Breast Cancer found 28 per cent of women with a family history of breast cancer said the would be deterred from having a genetic test if insurers had access to the results.