You are absolutely right about the parallels with Christmas and Midsummer - though the drink is a very traditional part of this day, which started as a day's holiday for the miners and their families, back in the nineteenth century (when a working class day out was in itself a political act).

But when I say 'the leader of the Labour Party' I mean the leader of the (national) Labour Party, the leader of Her Majesty's Opposition. Up to Tony Blair, the leader of the Labour Party always spoke at the Gala, and when he (always 'he') was Prime Minister, well, then the Prime Minister spoke. Tony Blair was the first to decide that this wasn't the sort of event he wanted to be associated with (despite being a Co. Durham MP); we hoped that Ed Milliband would be a different kind of leader. Apparently not.