A crisis in the supply of donated blood will occur again unless "outdated, illogical and unequal" rules that ban sexually active gay men from donating blood are reformed, the Tory MP Michael Fabricant has said.

The former government whip is calling on the government to change a law dating back to the initial outbreak of HIV/Aids in the 1980s, which bans gay men who have not been celibate for at least 12 months from donating blood.

In an article for the Guardian, Fabricant writes: "In January last year, parts of England and Wales came within three days of running out of a blood group. With outdated, illogical and unequal rules for blood donation, such crises are likely to recur. The rules on blood donation need to be changed to reflect modern medical science. Safety for the donor and recipient of blood transfusions must of course be respected, but fairness and equality need to be considered too."

Under the rules introduced in the 1980s, gay men were banned completely from donating blood. This was amended in 2011 to prevent gay men who have had sex in the past 12 months from donating blood.

Fabricant says the ban is discriminatory because a gay man having safe sex is banned from donating blood while a promiscuous heterosexual man having unsafe sex is allowed to donate blood. He writes: "If you are a gay man and you have not been celibate for 12 months or more, you are forbidden from donating blood – even if you have been practising safe sex. By contrast, if you are straight but promiscuous with multiple partners and practising unsafe sex, you can. This is wrong."

The MP says the ban shows that the "cause of equality still has barriers to break", even after the historic introduction of equal marriage legislation. "Against this background of huge social change in the cause of equality, it is still forbidden for a sexually active gay man to donate blood. Is it based on science? Or is it still based on the 1980s view of HIV and Aids?"

Fabricant says other groups are more likely to have a higher risk of HIV infection. "Thankfully, HIV is no longer the killer disease that it once was, though it still cannot be cured. But its detection is almost instant, so anyone with HIV can be prevented from donating blood. HIV is not unique to gay men; it is prevalent in straight people too. If a gay man practises safe sex, and can prove he does not have HIV, why should he not be able to donate?"