The following website (from a Christian Schools group) links to a number of interesting references on the topic.
The legal implications discussion in the paper by Foster is particularly noteworthy for setting out what has actually happened around the world. I was particularly intrigued by the Court judgement:
" ‘To distinguish between an aspect of a person’s identity, and conduct which accepts that aspect of identity, or encourages people to see that part of identity as normal, or part of the natural and healthy range of human identities, is to deny the right to enjoyment and acceptance of identity.’
In essence, the court was saying that to criticise homosexual sexual activity is to attack those people who identify as homosexual. In particular the following quote at  from the UK Supreme Court decision in Bull & Bull v Hall & Preddy  1 WLR 3741 was supported, where Lady Hale said:
‘Sexual orientation is a core component of a person’s identity which requires fulfilment through relationships with others of the same orientation.’ "
Will it be permissible to suggest in any context (eg. religious school) something contrary? How can it be permissible to discriminate against conduct, when to do so is held to be discrimination on the basis of identity? Does the court deny that a person who holds they are homosexual might also hold the view that same sex sexual relationships are wrong?
And finally, this is the Catholic Bishop’s Pastoral Letter: