The CCHQ defence of the turnout in Labour’s mayoral primary being the best part of ten times higher than our own – roughly 88,000 to 9000 – will be, first, that Labour was conducting a leadership election at the same time as its mayoral selection and, second, that a higher proportion of its members are concentrated in the capital (estimates vary from a fifth to as much as half).

Obviously, both factors played a part in shaping the difference – particularly since Labour opened up its voting to new categories of voters: registered supporters and affiliated supporters, who were able to sign up at reduced rates.

However, this picture is not a full one.  The Tory turnout is down by almost half since last time round: as Stephen Bush points out over at the New Statesman, Boris Johnson got 15,661 votes in the last Mayoral primary, compared to 6,514 for Zac Goldsmith in this one.

It may well be that his thoroughly-anticipated win depressed turnout. Or perhaps that Party membership in London is down: but CCHQ has been insisting for the past two years that it is rising overall. Then there is the vexed matter of VoteSource’s performance.

At any rate, complacency would clearly be out of place, and CCHQ will want to take a long hard look at why our primary turnout is lower than for the last selection, and Labour’s is so much bigger for this one.  None the less, primary turnout is not an infallible guide to election results (including next May’s)

So congratulations to Goldsmith – but also to Andrew Boff, Stephen Greenhalgh and Syed Kamall.  I was impressed by all of them when chairing a Wandsworth and Wimbledon Conservative hustings, and their endeavours have helped to elevate this contest.  I hope that Greenhalgh and Boff – Kamall will presumably be unavailable – will play a future role in the Goldsmith mayoralty that we must all now work for.