Opinion polls on politicians should always be treated with caution, for the simple reason that many of those surveyed will know little or nothing about the figures in question.
But with Labour immersed in its first leadership contest for 16 years, the latest PoliticsHome poll may make more of an impact. The poll found that Jon Cruddas is Labour's most popular politician, with an approval rating of +3. He is the only Labour figure with a positive rating, although only 27 per cent of the public had an opinion of him.
That Cruddas has never held ministerial office means that he has not been required to take the sort of decisions that can alienate the public. But I'd be surpirsed if his affable, open style didn't also benefit him.
Of the leadership contenders, Andy Burnham fares best, with an approval rating of -2, followed by Ed Miliband on - 5, David Miliband on -7 and Ed Balls on -39. Of the four, more of the public (61 per cent) had an opinion on Balls than any other candidate.
Findings like this should concentrate Labour minds. It would be politically irresponsible to elect a candidate so clearly disliked by the public.
Meanwhile, despite the noble efforts of my colleague Mehdi Hasan, Vince Cable remains Britain's most popular politician, with an approval rating of +24.