Now the complete ban is being lifted.  Until now, any man who had ever had sex with another man was barred for life from donation.
From 7 November the ban is being lifted in England, Scotland and Wales.   But men who want to donate must not have had sex with another man in the past 12 months.
This deferral period has been left in place because there is a "window period" after infection with blood-borne viruses where they are not detectable.
This window period is far less than 12 months.
The report from the Advisory Committee on the Safety of Blood, Tissues and Organs (SaBTO) says that for HIV it varies from nine to 15 days, depending on the type of test.  For hepatitis B, which causes liver disease, it is 66 days.
In Spain, the deferral period is six months following the change of a sexual partner, whether the would-be donor is heterosexual or gay.  In Italy the restriction lasts for four months following the change of partner.
By contrast, in the US, Canada, France and many other countries there is a complete ban on donations from men who have ever had sex with men.
Whilst welcoming the lifting of the ban in the UK, some still regard the one year deferral as too long.
Stonewall Chief Executive Ben Summerskill. "To retain a blanket ban on any man who has had sex with another man in the last year, even if he has only had oral sex, remains disproportionate on the basis of available evidence."
But Sir Nick Partridge, Chief Executive of Terrence Higgins Trust said: "The remaining deferral regulation for sexually active gay men is based on their heightened risk, as a group, of sexually acquired blood-borne viruses."
A one year deferral period for donation applies to other groups as well: for example anyone who has been sexually active in countries where HIV/Aids is very common, and anyone who has had sex with a prostitute.
NHS Blood and Transplant has a complete list of who can and cannot donate.
The hope will be that the shift in policy will lead to an increase in the number of donors.
If you want more detail about the reasoning behind the decision to lift the ban, then the full report from the Advisory Committee on the Safety of Blood, Tissues and Organs (SaBTO) can be read here.
When I reported last year about the urgent need for blood donors I received many comments from gay men that they would like to donate but were unable to.