In more than 30 years of attending party conferences, what is the least funny joke I’ve encountered in a speech (exempting the many for which I have been personally responsible)? There are plenty of contenders. The moment when one of John Major’s cabinet ministers asked if Tony Blair had any principles, produced a shopping bag from the Principles retail chain, declared it empty and threw it over his shoulder, is definitely up there. But my personal favourite came from John Redwood, who isn’t quite the gagmeister you fondly imagine him to be.

“Step forward Ian McCartney and walk tall among the men,” he challenged the party conference in 1997. This required his audience to know who Mr McCartney was (a junior minister in the Blair