Northern Ireland is being called on to defend its ban against gay men giving blood.
Jeremy Hunt, the Northern Ireland Health Secretary, has previously claimed banning 'gay blood' is needed to ensure public safety.
He has begun a legal appeal after a judge ruled it was up to him if gay men could donate blood in NI. A ban, which was enforced during the 1980s, 90s and 00s, was lifted in England, Scotland and Wales in 2011.
New rules allow gay and bisexual men to donate blood as long as their last sexual contact with another man was more than a year ago.