Originally Posted by Chris

The Speaker of the House of Commons is a bloody powerful individual, it's just that circumstances are rarely so dire as to give the one who holds the office the opportunity to make maximum mischief. Much of what he can do rests on convention rather than statute but the problem there is that just about everything the Commons does is based on convention, and the Speaker is the final arbiter of how convention applies. There is no way to appeal any decision he makes. So if you are saddled with a Speaker who is prepared to pick and choose which conventions he will uphold, there's very little that can be done, short of having Her Maj send him to the Tower to relieve his shoulders of the burden of supporting his enormous head.