News that insurance companies this week agreed to a five-year voluntary ban on using genetic testing to set premiums was welcomed by patient groups and MPs concerned about the possible development of an uninsurable "genetic underclass."

Anyone fearful that they risk being denied cover, or landed with unaffordable premiums after genetic testing, can breath a temporary sigh of relief.

The Alzheimer's Society, one of the most vociferous opponents of the use of genetic tests, applauded the ban. "It's fantastic. We have been campaigning on this issue since 1994," a spokeswoman said.

But GeneWatch, a science and policy group, described the move as "hopelessly inadequate". Deputy director, Helen Wallace said: "We do not think a voluntary agreement is sufficient to protect people from discrimination and there should be a legal ban in place."

This week's deal means individuals will not be required to disclose genetic test results to insurers unless they are buying a policy paying out more than £500,000 on death, or £300,000 on critical illness. The ABI says 97% of policies are below these levels.