The Sunday Times and the Telegraph have both done some digging into the Conservative Party's returns to the Electoral Commission and found that only about 3 in 5 accounting units (groups of branches in the Conservative Party's organisational structure) filed returns and of those only about a quarter returned membership figures.
If the Conservative Party's membership has dropped that low (from over a quarter of a million when David Cameron took over as leader 8 years ago) then it's frankly astounding. It would mean that their councillors made up 15% of their whole membership and that doesn't include parish councillors. They probably have 4 or 5 times as many parish councillors as they do for the councils above so even allowing for perhaps a quarter of them being double jobbing councillors, as much as 60% of their membership could be made up of their councillors.
Even if the Conservative Party's membership was as high as 100,000 - which appears to be a psychological barrier for the membership - then Conservative councillors could still make up as much as 35% of their total membership.
The youth wing of the Tories, Conservative Future, is struggling to keep and motivate members whilst previously active members are leaving in droves either for UKIP or just turning their backs on politics altogether. Even with the most optimistic estimate of 100,000 members, the Conservative Party must be completely devoid of activists.