The conditions for when a snap election can be called have been significantly restricted by the Fixed-term Parliaments Act 2011 (FTPA) to occasions when the government loses a confidence motion or when a two-thirds supermajority of MPs vote in favour. Prior to this, the Prime Minister of the United Kingdom had the de facto power to call an election at will by requesting a dissolution from the monarch – the limited circumstances where this would not be granted were set out in the Lascelles Principles.