Does the Speaker need to be an MP?

As the election for Speaker of the House of Commons gets underway, complete with the Daily Telegraph checking each and every candidate's own expenses claims, one has to wonder if in the current environment there is any sitting MP who could command sufficient public confidence in the role to make the necessary changes. But does the new Speaker have to be an MP at all?

Now it's quite possible that there are various laws, standing orders and conventions that currently require the Speaker to be an MP. But then there are various laws, standing orders and conventions about MPs' expenses and look where those got us! And since no Parliament can bind its successor these could be changed.

So would it be worth a thought to looking outside the present House of Commons for a candidate to be Speaker? Is there be somebody who has not been part of the current mess who has a track record on fighting corruption and who commands public respect? And if so, why not change the present way of doing things to allow them to be brought in? Does anyone know of a reason why we can't?