Campaigners are hoping the ban on gay men giving blood in Scotland is closer to being overturned.

Rob McDowall will call for the current policy on not allowing men who have had sex with men to donate their blood to be removed when he makes his case to the Scottish Parliament's petitions committee today.

"Since the 1980s, the British government has tried to brush AIDS and HIV under the carpet and affix this disease to the gay community – a scary shadow of homosexuality that dare not show its face in modern-day blood transfusions," McDowall said The Scotsman.

The rules mean fewer people can currently give blood, potentially putting lives at risk if a lot of blood is needed in the event of a disaster.

"This outdated, homophobic and offensive rule must be changed to allow gay and bisexual people to give the gift of life," added McDowall.

But the blood donation service ScotBlood has dismissed claims and said it had a duty to make sure patients got the safest blood possible.

"While the absolute number of cases of HIV in heterosexuals diagnosed annually is greater than for men who have had sex with men, when the size of the respective populations is taken into account it can be seen that the relative risk of exposure is very different," said Dr Brian McClelland, from the Scottish blood service.

"Figures would indicate a man who has had sex with a man is seven times more likely to contract HIV than a heterosexual," he told the publication.

"Abolishing the rule for gay men would increase the risk of an HIV-infected donation entering the blood supply by about five times, and changing the rule to allow gay men to donate one year after they last had sex with a man would increase the risk by 60 per cent."

The LGBT Network said safe sex practices meant men who have had sex with other men could give blood and stressed that there were no restrictions on heterosexual people who have unprotected sex giving blood.

Patrick Harvie, a Green MSP, supports the petition to end the ban and wants a review of testing procedures.

"The procedures are outdated and if we had better testing, the issue of people's lifestyles and the origin of the blood would become irrelevant," he said.