This question posed by an American in our office. Tony Blair will today go to the Queen and ask her to dissolve, etc etc. Of course this is a ‘formality’. “There would be a constitutional crisis,” I replied rather lamely. I suggested that emergency legislation would remove the formality PDQ, but I have no idea if this is the correct answer or not. For all I know Tony would nut the Queen and walk off laughing.
When I sat down to write this entry I was a bit embarrassed – this is one more weird constitutional accretion that comes from having a residual monarchy. But actually you do need some way of formalising important things like calling an election and forming a government, and having it based on a particular conversation between two people seems a less loophole-baiting method than some.