Tracing the claim: Do 48% of Labour members live in London?

This claim has been circulating on Twitter for a couple of days now but it's not clear where it originated or indeed wither it is true or not. The Labour Party do not break down membership data by region — or at least they don't make that information public.

The first tweet of the claim appears to be from the UKIP MEP Patrick O'Flynn on Tuesday. We are awaiting comment from Mr. O'Flynn who is attending his party's conference in Doncaster today. The only other written mention of this claim we can find is on the website of communications firm Guide Consultancy who hosted The Guide Steak Club, a private dinner for politicos and public affairs professionals earlier this month.

"At this week's GUIDE Steak Club with the Telegraph's excellent Stephen Bush, it was pointed out that 48% of Labour members live in London, which goes against the idea that there are unassailable seats anywhere outside the capital."

Stephen Bush, assistant comment editor at the Telegraph, who was a special guest at the dinner, told us that he had heard the figure when he was in a previous position covering a Labour party special conference in March. He said that he was told by a Labour Party official that "almost half" of the party's members were in London and surrounding satellite town in the Home Counties and the actual figure for London only was around 40%.

We then contacted a former colleague of Mr Bush at the LabourList blog also familiar with the 40% figure who says he was told it by a Labour party PPC [Prospective Parliamentary Candidate] "in the North." Here our trace comes to an end.

Without access to the Labour Party's internal data we can't tell what the London membership might be. However calculations published in the journal British Politics last year suggest that 21% of Labour members live in London. The authors used public distribution data about sent ballot papers to its members before the Labour leadership election in 2010 and  then isolated the numbers for constituencies in the Greater London region. We came up with the same result when we ran the same calculation on the underlying data.

We do not have a more up to date figure and so we can't say if the claim of 48% membership in the London area is correct or not.