The House of Commons has prayers before each day's sitting .No doubt the Speaker would say that Prayers do not form part of the business of the day . The point in the instant case is that this council insisted on prayers as part of the agenda, part of the business of the meeting. If these Christians wish to hold prayers separate from, and held before, the formal meeting they may, presumably, do so within the law.
And to say that it must continue because 'it is traditional', as some argued, is surely the stupidest argument to justify anything. It's saying 'because our ancestors and predecessors did it, it must be right'. Bear-baiting, anyone? Executing witches? Trial by Ordeal? :-)