It is now almost inconceivable that David Cameron would not ballot Conservative MPs on any coalition deal – with the Liberal Democrats or anyone else – were he not to win a majority in May, but be in a position to explore forming a second multi-party government.

The Times’s report of Grant Shapps’s interview with it last weekend was an important piece of evidence to support this view.  Graham Brady, the 1922 Committee Chairman, has referred in print to settled “protocols” between Downing Street and the committee.

Cameron himself will have been reluctant to concede a ballot, since a coalition proposal is more likely to be voted down in secret than in a meeting – especially one in which speakers will have been lined up in support by Number 10, as was the case five years ago.

However, Downing Street recognises that it is between a rock and a hard place in such an eventuality since, in the words of one member of the executive, “if a ballot was not organised by the whips we would simply organise one ourselves”.  It has little alternative but to go ahead.

The conventional wisdom is that though MPs will be balloted party members will not be.  CCHQ points to difficulties in setting up such a ballot in good time, arguing that definitive membership lists are held by local Associations and not in Millbank.

However, one of the reasons why membership has risen slightly is that CCHQ has got a better grip of it – having enough centrally-held data to persuade enquirers that the increase in members is real.  There has been a shift to central membership as a proportion of the whole.

After all, it isn’t so long since CCHQ was claiming that it was impossible to release membership figures at all – before a campaign led by this site caused it to do.  If the Liberal Democrats can find a way of gaining membership approval, the argument runs, then so can the Conservatives.

And despite reports that party members will not be balloted, Number 10 hasn’t given up on the idea of consulting them in some way.  “We realise that in the event of a coalition the wider party would have to be involved,” a source told ConservativeHome.

That form of words falls some way short of the secret ballot that Tim Montgomerie called for last Saturday, and this site has urged previously.  What else could it mean?  Consultations of Association Chairmen by phone? Special meetings in each region?  In each area?

Whatever may happen, we believe that party members would be very unlikely to reject a deal that Tory MPs had already accepted.  A ballot endorsement would given a future coalition legitimacy from the start.  This one would run more smoothly had it been in place this time round.