University students in the Midlands have criticised the National Blood Service for its refusal to accept donations from homosexual men.
The student unions at Birmingham and Warwick universities have joined a protest against the NBS's ban on gay donors, because of fears they will pass on diseases such as HIV.
As a result of the protest the NBS, which needs daily donations of 8,000 units, has raised fears of a large drop in the country's blood stock.
Last year the Birmingham University Guild of Students scrapped the NBS's stall at the university's freshers' fair.
Richard Angell, president of the guild, said while the union appreciated the importance of giving blood, it did not approve of the NBS being on campus at the same time as the Lesbian, Gay, Bisexual and Trans Students Association (LGBT).
He said: "This for us is a clear example of institutional homophobia and treats the LGBT community as if they are dirty and second class. We will not stand for this but wish to support blood provision in the UK."
The union ran a "Give Blood because we can't" campaign, which encouraged donors to bring a gay friend along to donation sessions in protest to the NBS's policy.
Brian Duggan, deputy president of Warwick University's student union, said students were encouraged to give blood at the university but the NBS had been made aware of the union's views.
"We obviously support the work the NBS do but are concerned about their policy," he said.
Dr Frank Boulton, lead consultant with the National Blood Service, said: "The National Blood Service implements a policy that men who have had sex with other men are excluded from becoming blood donors.
"Our primary concern is to ensure that the blood we provide for patients is as safe as possible.
"To minimise the risk of any blood-borne infection entering the blood supply we select donors who are at the least risk of infection, and also test all donations."