For obvious reasons we felt we had to tune in to Adrian Chiles’ radio 4 programme, ‘The Unheard Third’, in which Chiles explores the reasons why 18 million people – equivalent to a third of the voting population – didn’t vote in the last General Election.

A wide range of issues are discussed, including confusion about the voting system, the flaws in first-past-the-post and how cynicism about today’s politicians is keeping people at home. Perhaps most striking was the discussion about how a decline in tribal loyalties, particularly on the Labour side, has left millions of would-be voters feeling disenfranchised. Here’s John Curtice, who points to New Labour for declining turnout among traditional working class voters…

It airs again at 8pm tonight on Radio 4…