>>Technically the Prime Minister can do anything as long as the Queen rubber stamps it.
Blair would not let the Trident issue go to a vote if he wasn't sure of a victory.<<
Really? Thanks for the education. In a way, that makes the Prime Minister more powerful than a President.
Technically the Monarch is the source of all power, but in reality the Government rules. That was what all the chopping of heads was about!
I'm not sure if it is the same in Canada, Australia and New Zealand as the Queen of the UK is also the Queen of those countries as well, but I presume it is to a certain extent.
It is also why those countries (along with the US) are so close to each other.