First of all, it's not a gay blood donation ban! No, I'm not ranting about Trans exclusion this time, but a wider issue - it banned bisexual men too, but lesbians are OK. It's a ban on donations from men who have had sex with men. Or MSM, for short, because that's a bit of a mouthful.
The reasons for the old rules were that men who have sex with other men are at a slightly higher risk for HIV. And yet other significantly higher risk groups, such as anyone engaging in unprotected sex with multiple partners or who comes from certain parts of Africa, were not excluded. Why not? In the latter case, it would be "racist" to discriminate, apparently.
The message this sends to other people - who see the questions on the forms when they themselves give blood - is that gay men are somehow dirty, reinforcing the fallacy that gay men pretty much all have HIV. In reality, most HIV positive people in the UK are straight and the vast majority of gay men do not have HIV.
But we've just heard the rules have been changed! That's good, isn't it? Yes, that it's a one year ban rather than a lifetime ban is definitely a step in the right direction that those involved in campaigning can be very pleased with. We're not there yet though, as most men are going to have had sex in the past year, which if you're gay rules you out.
Bisexual, not gay, men are most likely to gain from this. If you happen to currently be in a monogamous relationship with a woman, you're OK. (It's not mentioned but one presumes that a woman in a relationship with a bi man who hasn't had sex with another man for over a year is now also able to give blood)
And finally... are you a straight or bi woman? You can't give blood if in the last year you've had sex with a bloke who has had oral or anal sex with another bloke. Because that's the sort of thing that you always find out from a bloke before you take him to bed, right?