The government has published a response to a petition to 10 Downing Street on Removing Collective Worship from non-faith schools.
All community, foundation or voluntary schools MUST offer a daily act of collective worship which is broadly of a Christian character in keeping with the religious traditions of this country.
Schools can apply to the SACRE ... to have the requirement for collective worship lifted [So it's NOT compulsory like you just said after all?]
... if it is not appropriate for the pupils in their school. [So christian worship is appropriate in a non-faith school?]
... collective worship provides the ... unique opportunity to [do all sorts of other things that are not worship! that could be done in other non-unique ways]
Parents have the right to withdraw their child from collective worship [but only by creating a hullaballoo, and singling their child out for special bullying.]