I am really wondering why people think the Blairs should foot the entire bill for this party. Just because they can afford it?
I have a suspicion my neighbours are richer than me - shall I ask them to pay the entire cost of replacing a jointly owned fence just because they are richer than me and they can afford it?!
£10 for an end of Y6 party seems reasonable and it sounds such a treat to go to their mansion. They are providing this fabulous venue at a cost of £0 to the guests and people are ungrateful!! If I was Blair, I would cancel the party. The head had put in place arrangements for those who genuinely could not afford the £10 but Blair is still being dragged through the gutter press.
FWIW I don't even like Blair's politics but he does seem to be a decent person and nobody has the right to freeload off him, or his family.