“Nothing”, wrote Momentum director and member of Labour’s NEC, Christine Shawcroft, in declaring her support for Jon Lansman’s bid to be the party’s next General Secretary, “would induce me to support a candidate from a major trade union, they stick it to the rank and file members time after time after time. It’s also time to support disaffiliation of the unions from the Labour party. The party belongs to us, the members”. 

She’s since deleted the post.  Nevertheless, the reaction has been understandably furious.  Not only was organized labour instrumental in founding the party in the first place but many affiliated unions have, very much more recently, provided invaluable moral and financial support for its current left-wing leadership. Arguably, then, the party belongs just as much to them as it does to the members.

But even pointing this out is effectively to acquiesce in what is a false distinction between ‘rank and file members’ – including, ironically, members of Momentum itself – and the unions.  That’s because many of those self-same members also belong to those self-same unions.  In fact, research by the ESRC-funded Party Membership Project based at Queen Mary University of London and Sussex University reveals that around a third of grassroots Labour Party members are union members too – a far bigger proportion than is the case for any other political party in the UK.

It is worth noting that the proportion of Labour members who belong to unions seems to have dropped as the party’s membership has ballooned in the wake of Jeremy Corbyn standing for the leadership – but not by that much.  When my colleagues Paul Webb, Monica Poletti and I surveyed Labour’s membership just after the 2015 general election, some 39% of party members belonged to a union.  When we returned to survey the party just after the 2017 election, the figure was 32% – still way over the 5% of Tories, 11% of Lib Dems, 7% of Kippers, 21% of Greens, and 15% of Scots Nats, but admittedly down on two years before.

If we look in more detail at those people who joined Labour during and after the leadership election of 2015 then it becomes apparent that they are less likely to be union members than those who were members before Jeremy Corbyn declared his candidacy and then won the contest.  Probably around a quarter of these new joiners are union members.

Now, what we can say for certain about those Labour Party members who also see themselves as members of Momentum is limited, because, on our figures anyway, ‘only’ one in ten Labour members reckon they belong to the organization, thus giving us only small sample size.  However, inasmuch as we can tell from our respondents, nearly half of them are trade unionists.

Those figures don’t necessarily send a ‘delete your account’ message to Ms Shawcroft, but they do suggest that her belated discretion may have been the better part of valour.

Tim Bale is Professor of Politics at Queen Mary, University of London