Labour’s leadership election has revealed some intriguing tensions between their parliamentary party and their grassroots. MPs have an important role in the shortlisting process – candidates who don’t secure over a certain number of MP nominations are automatically disqualified. By contrast, the endorsements of Constituency Labour Parties carry no formal weight but can allow the party’s members to express a public view on whom they prefer.

The ideological gap that has been revealed by the surge of CLP endorsements for Jeremy Corbyn is fascinating – as others have reported, it is likely the product of a combination of the hard Left being organised enough to pack out CLP meetings and a genuine shift leftwards brought on by new members inspired to join by Ed Miliband’s doomed rhetoric. It’s remarkable in itself that Corbyn should have been a struggling candidate among MPs, only making it over the line due to charity nominations from some who didn’t actually support him, but has now become the apparent hero of the hour for a large chunk of the grassroots.

However, some CLPs are more equal than others. Those in Tory heartlands, for example, are likely to have fewer members than those in Labour-held seats. Is the fracture between the centre and the base occurring on the fringes of the Labour Party or in its heartlands?

This is a little tricky to measure. There are helpful tallies of both MP nominations and CLP endorsements being kept by the New Statesman. But while 209 CLPs have so far chosen a preferred candidate, many of those are not in Labour-held seats. With all due respect to the members of Witney Labour Party, their preference for Yvette Cooper is slightly less interesting than, say, the views of those in Newcastle upon Tyne Central or Blaenau Gwent. By the same token, a lot of CLPs in Labour-held constituencies are yet to vote on who they might endorse.

So to what extent is the Corbyn surge happening in Labour territory? By my count, 27 CLPs in Labour-held seats have endorsed the bearded lefty.

Ten of those seats also have MPs who nominated Corbyn for the leadership. For three more, their local MP did not nominate anyone (perhaps hoping to avoid diverging too publicly from the politics of their local members).

The remaining 14 CLPs are of particular interest – these are local parties which have chosen to disregard the urging of their MP and plump for Corbyn instead.

At the most jarring end, there are five MPs who nominated the Blair-ish Liz Kendall but whose CLPs have now voted for the purity of the hard left: Gloria De Piero in Ashfield; Jim Dowd in Lewisham West; Julie Elliott in Sunderland Central; Mark Hendrick in Preston; and Nick Smith in Blaenau Gwent.

Four of the MPs backing Yvette Cooper have suffered the same experience: Jon Ashworth in Leicester South; Geraint Davies in Swansea West; Vicky Foxcroft in Lewisham Deptford and Sharon Hodgson in Washington and Sunderland West.

Five Burnham-supporting MPs, too, have found their local party is further to the left than they are – Carolyn Harris in Swansea East; Gerald Jones in Merthyr Tydfil; Ian Mearns in Gateshead; Rachel Reeves in Leeds West and Iain Wright in Hartlepool.

Labour aren’t the only party whose grassroots sometimes disagree with its MPs – there are plenty of issues on which Tory MPs have differed from their local associations. But issues of conscience, or individual policies are one thing – there is a vast difference in worldview between an MP who believes Liz Kendall is the future of Labour and a CLP which thinks Jeremy Corbyn is the bearer of that torch. Such a gulf is embarrassing in the short term, but in the longer term it could be very troublesome indeed.