David Cameron’s campaign to detoxify the Conservative party brand took another step forward this week as he renewed his commitment to “the progressive aims of reducing poverty, fighting inequality and increasing general well-being”. Calling on “big society” to mend “broken Britain”, the Tory leader’s Hugo Young lecture marked another outing for his vision of “progressive conservatism”.

But what the speech really revealed was his failure to appreciate that progressive politics is about more than warm words. It has a distinct ideological history markedly at odds with the policies Mr Cameron wants to implement as prime minister.