As routine, in our party we use some kind of short-listing for almost every elected position when there are more than two candidates. We expect successful candidates to have a majority support amongst the membership, not just a plurality, even if this means that the candidate who was second in the first round of voting ends up being selected. I'm guessing (and please correct me if I'm wrong) that there is not a single Tory MP who has been selected using pure, unfiltered, FPTP.

I would have more sympathy with FPTP if we ever – and I mean ever – used it for internal party elections.

But the system is packed with history and tradition and we in our party love all that. Traditions like:

OK. I get it. We're the Conservative party. We think our title is an adjective rather than just a noun. So when a change is proposed to the voting system our instinct is to oppose unless there is a very good reason for changing it.

We do this because party members want to see candidates that represent majority consent. So why is it that we don't respect the electorate enough to give them the same benefits?

I cannot, for the life of me, understand why, when given the choice between a two-candidate election system and one that's designed to filter out less popular choices, that we should opt for the clapped out, unfit-for-purpose system that is FPTP.

I'm also guessing that our 'No' supporters don't really support the principle of choice through plurality.

Are they suggesting that an unfiltered list of candidates for the next by-election, for example, should be presented to the members of that constituency party on an FPTP basis without an exhaustive ballot or some kind of short-listing process?

Would they want to see a full list of leadership candidates presented to the membership and a leader selected on the basis of a simple plurality?

No, of course not. Though David Davis might.

Every internal election in which I have taken part in my 37 years of membership we short-list, we rank or we have exhaustive ballots. I cannot remember a single occasion where we presented a full list of candidates and voted on an FPTP basis. Why? Because to do so would be unfair; not unfair to the candidate but unfair to the electorate. Yet this is exactly what a 'No' vote would achieve. It would legitimise an hypocrisy.

AV provides for that short-listing, that exhaustive balloting, on one election day. In France they do it in two elections. For the Party leadership we have two elections with different constituencies but it all amounts to the same: reducing the number of choices down to two which can then reveal majority support.

The 'No' campaign compares AV to other systems of election but not FPTP. They know that FPTP is like tossing a coin on three possible choices - it doesn't work unless you do it more than once.

An increasing number of Tories will vote tactically to keep out their least favoured candidate. Some Conservatives believe this is close to heresy. I prefer to think of it as being close to reality. I know an ex-Tory MP who routinely votes LibDem in elections because he judges this the best way to keep the Labour Party out. I've lost track of the number of “Can't win here” graphs that I've put into election literature to encourage people to vote tactically. A tactical voter has to guess what her/his neighbours are doing and rarely vote for the party they really want. I want 3rd place Conservatives in Islington to be confidently vote Conservative AND help to keep out their least favoured option. I think it would reveal that they aren't third place after all.

This is probably our last chance for decades to change this rotten, unfit-for-purpose, clapped out system. And that's why I'm voting for AV. What's not to like?

> The website of Conservatives say Yes to AV.