Dear Stephen Dorrell: Millions of people lose each week on the Lottery. A Cardiff cancer charity stands to lose a lot more. Its secretary calls on the Heritage Minister for compensation to protect its work

I am sad to tell you of our decision to withdraw our lottery operation, which has been promoted within supermarkets throughout England and Wales.

The decision is a direct result of the introduction of the National Lottery. Just 12 months ago, we had 150 lottery kiosks, which provided half the charity's annual income of about £3m. Today, only 35 remain and the income from these has been cut to a level where they can no longer trade profitably.

Let me explain to you how useful income from our lottery has been. Tenovus was set up in 1943, but it only became a force in cancer research in the Sixties. We now have two of our own research laboratories: one in Cardiff, which specialises in breast cancer, the other in Southampton, which has done award-winning work on leukaemia and other cancers. About 70 Tenovus- funded scientists work at these labs.

Drugs such as tamoxifen, used worldwide for the treatment of breast cancer, were developed with the assistance of Tenovus scientists, who have also been at the vanguard of radical antibody treatment for leukaemia and lymphocytic cancer.

We employ a team of nurses and social workers who staff a freephone cancer helpline (0800 526527), which has helped more than 12,000 patients.

Our instant scratchcard lottery, set up in 1978, has been vital to funding this work. Until the introduction of the National Lottery, we sold about 8 million tickets a year. The prize was £5,000 a month. Last autumn, we tried for a short time to attract more custom by increasing the prize to £25,000, but that meant we could only give a prize once every three months.

Before the introduction of the National Lottery, we made extensive inquiries to find new outlets for our lottery, but to no avail. News that medical research charities will be excluded from funding by the national lottery charities board only compounds our difficulties.

This is not the first time we have suffered from government legislation. Tenovus originally enjoyed income from a charity football pool organised under the 1971 Pool Competition Act. After the introduction of the Lotteries and Amusements Act of 1976, we were encouraged to use this to cover our fundraising. But this left us with no protection when the National Lottery came along. We lobbied for protection when the National Lottery Bill was being passed, but got no joy.

The National Lottery has caught the public imagination. But it seems inevitable that Tenovus will not be the only casualty from its success. Our lottery has contributed more than £10m to our care and research programmes.

These are secure for the next two years, but I ask you to support our request for compensation so that we can continue our work for this and future generations.