“There it is,” we wrote recently of Robert Goodwill’s challenge to Graham Brady for the chairmanship of the 1922 Committee’s executive, “unless a third contender comes along. Or more.”

Lo and behold.  Last week, Heather Wheeler threw her hat into the ring.  So at least three candidates will slug it out after June 21, when the poll is due to take place.  Which raises a question.

What system will be used for the election?  When Brady and Bill Wiggin went up against each other for the chairmanship near the start of this Parliament, there was no need to ask.

Nor when Brady and Richard Ottoway were competing candidates in 2010.  If you have only two candidates, after all, first past the post is what you’re left with – de facto if not de jure.

One has to travel back in time to 2001 to find a three way contest for the post, and even then transfers would have made no difference.  Michael Spicer defeated Gillian Shepherd by 13 votes.  The third candidate, John Butterfill, won eleven.

So, then: back to the coming election.  The conventional wisdom is that the more candidates stand, the better the incumbent’s chances of gaining at least a plurality of votes.

Unsurprisingly, sources close to the Brady camp are gung-ho about the prospect of a first past the post contest, and those close to the  Goodwill and Wheeler camps less so.

ConservativeHome is told that senior sources on the committee are pro a first past the past poll, and that a final decision is expected when the ’22 Executive meets this Wednesday.

There are arguments back and forth for first past the post and the alternative vote in this election, though they come at a time when the Government is planning to put even more eggs in the basket of the former

It wants to change the system used in England’s mayoral elections from the supplementary vote to first past the post.  (A proposal to switch to the alternative vote for elections to Westminster was trounced in the 2011 national referendum.)

So the dice seem to us to be loaded against change.  Not that the tactical calculations are always right: for example, it isn’t necessarily the case that the candidate expected to get out in front actually does so.

The best-known instance of a surprise in an internal Conservative election goes back to 1975, when a challenger upended an incumbent: Margaret Thatcher defeated Edward Heath by 130 votes to 115 (with Hugh Fraser gaining 16).

She had the momentum with her from then on, and went on to storm the contest on the second ballot.  That system, of course, is dead: Conservative MPs now put two candidates forward to party members.