And so comes the news that Speaker Michael Martin is to stand down today. (STV: Michael Martin will stand down today, STV news has learned for those who haven't yet seen it.) It is necessary that this has had to happen, but sad for the man himself.
Unfortunately for Michael Martin there is still a Commons vote on him to come. By convention, in order to keep the Speaker's position neutral from the government it is always the Commons who passes a resolution directly petitioning the monarch to confer a peerage upon the retiring Speaker, instead of the Prime Minister of the day making a patronage recommendation. I hope that when the vote comes MPs will take into account Martin's whole service and record, not merely his actions in the last few weeks.
This leaves the question of who will be the new Speaker. Now the traditional convention here is frequently misquoted and is difficult to summarise succinctly. It is not that the Speakership alternates between parties. Rather traditionally the initial candidate nominated for the Speakership is a government MP. In modern times only in 1992 has the government nominee been rejected, but that was primarily about the individual in question (who had literally just stepped down from the Cabinet), not MPs deciding to establish an alternative convention of rotation.
However much of this is now academic because of the new voting system. Instead of a motion to seat a named member, with amendments to replace their name with another, the new rules require a series of secret ballots in which candidates are eliminated until one has the support of more than 50% of those voting, who is then formally nominated. This means that all the traditions about "preferred candidates" and the like no longer apply.
However it shouldn't be taken for granted that the new rules will automatically deliver a centrist candidate acceptable to all (Alan Beith seems to be the man most touted for this role). Whilst the multiple ballots will allow MPs to change their mind in successive rounds, it is still possible for a polarised House to end up with a final choice of two figures who both have their detractors but both also have sufficient support to displace another candidate who could otherwise command much broader support. No voting system is perfect.
One thing that is clear is that there is no automatic Conservative right to the Speakership and claims to the contrary have no basis whatsoever.