Should private nurseries use children's centres?

 An interesting thread on Mumsnet in which a mum is a bit miffed that a local nursery brings eight-odd children accompanied by about two helpers to the children's centre stay and play.

Would nurseries be allowed to do this in the children's centres you work with? Is it a good thing because it boosts the number of children attending? Are the nursery children just as entitled to use the centres? Or is it a bad thing because the large groups may cause other children to be turned away? And should nurseries which are basically private enterprises use facilities run by the state? (Then again, a library is also run by the state and I shouldn't think anyone would object to nurseries taking children there).

I would be really interested to hear what people who work in the sector think. Go on, comment!