"All state schools in England conduct Christian worship. Why? Because they have to."
That's not actually true. All schools are required to provide an act of Christian worship, but how they actually interpret that varies so widely that it's fair to see some as religious, others as non-religious.
For our two local infant schools for example, one makes the children say grace at lunch, they sing hymns and pray in assembly and talk about god and Jesus as fact.
The other has no hymns, prayer, saying grace or presentation of the bible as fact. They interpret the "act of worship" requirement by asking the children to sit quietly in assembly for a few minutes and think about "wonder and awe" (concepts they've talked to then about previously).
The two schools are 10 minutes apart, both state schools, totally different approach. (We've gone for the non religious one, we much prefer it's ethos in general, including their stance on religion.)
And anyway, as has been mentioned, schools have effectively been given the green light to ignore the requirement these days anyway.
If people want to do something about it, perhaps an awareness raising campaign so the schools know they can ignore it now?