Adam Ramsay has just published a note on party membership in the wake of the Scottish referendum. His statistics reinforce the sense of the decomposition of the traditional political parties as their leaderships are captured by the corporate agenda. It is worth putting this trend into a larger picture. In 2011 the BBC ran a post on the possible “extinction” of political parties, no less. It assumed, as it would, that they could never be replaced by new ones. Michael Nienhuls created a logarithmic graph based on the party membership figures that the BBC reported for the Conservatives and Labour since 1951. Here it is.

You can see how Labour membership collapsed through the disastrous decade of 1970s, after the failure of the first Wilson government and the hopelessness of his second administration. Tory membership then dived after the defenestration of Thatcher to reach equally low figures by the start of the new century. It then continued at an even faster rate than Labour.

Which means that during the period between the elevation of David Cameron as the Tory party leader into the 2010 election and his becoming Prime Minister a remarkable thing happened. For the first time in the history of the UK, Conservative Party membership fell below that of the Labour Party.

The trend continues – quite dramatically. In 2011 the figures (as used in this graph) were Conservative 177,000, Labour 190,000. If Adam’s figures also drawn from the House of Commons Library are correct, they are now Conservatives 134,000 with Labour still on 190,000.

(My guess is that there was a Labour ‘churn’ with new members joining in the face of Coalition austerity and hope that Ed Miliband would provide a new direction, whilst his condemnation of the Iraq war made it possible for some to rejoin.)

The latest figures for the Lib Dems are also stark: down from 66,000 to 44,000 in three years having achieved their leaderships dream of participation in government.

The decline of political parties is a secular trend with a number of causes, such as the role of the media and the hollowing out of representative democracy. We are also familiar with the destruction of the trade union movement. But what shouts out from these figures and is less discussed is the catastrophe that has overtaken what was the traditional party of government, with its enormous network of Conservative and Unionist Party clubs and social centres.

John Strafford, wrote a devastating report on this for OurKingdom last year with all the authority of a long-standing member of the Conservative Party who had witnessed its decline from the vantage point of Beaconsfield. He reckoned that in reality its membership had fallen below 100,000. He warned his fellow Tories,

“Without change the Conservative Party is heading towards a disaster. By the time of the next General Election it will have ceased to exist as a membership organisation.”

He then concluded,

“I sometimes think that the Conservative Party has a death wish. Lack of historical knowledge, lack of experience and lack of strategic thinking mean the Party is slowly walking into oblivion. This scenario can be changed, but time is running out.”

Perhaps this judgment applies to the Westminster system itself. In Scotland at least there are signs of renewal post the referendum.

PS on 28 September: Conservative Home are reporting that Conservative Party membership is now rising and is now just below 150,000, up by 11 per cent. That is before you delete the recent defections to UKIP. The critical issue with all these figures, as I have tried to argue, is the relative one. If the flat Labour conference and lack of self-belief among its supporters hollow out its membership then the signal advantage Labour have gained will be dissipated at a time when a handful of seats can make all the difference to who governs.