How can non-religious organisations be included in a review of a subject about RELIGIOUS Studies? Remember that the humanists here are determined to make it clear that their belief system isn't a religious one!!
I'd have thought that a clear policy on what constitutes RE is needed, and it may be there is one - since this doesn't affect Scotland (education here is fully devolved) I don't know if there is or not.
In my view RE in the state school system should contain no acts of religious worship or observance but should address the cultural, political, historical and social aspects of religion in general, which should of course included details of the tenets of different religions. As such it would be appropriate to include non-religious perspectives on issues that, in a sense, compete with religions, such as morality and also the justification of religious institutions having special status in the public arena (such as the C of E and Bishops in the HoL), which makes secularism highly relevant to RE.
I can't see either, in terms of the domestic situation here in the UK, that the issue of the decline of Christianity can be avoided given the series of studies that indicate this, where a recent study showed that here in Scotland the majority now have no stated religious affiliation.