Allowing for the characters nominated by the three main parties to be Mayor of London, it was perhaps inevitable that a story of a sexual nature would emerge at some stage in proceedings. The post does, after all, have form in this respect, with Steve Norris, the Conservative contender on the past two occasions, having been exposed once as a man with five mistresses (not at the same time, he insisted) and the Liberal Democrat champion last time, Simon Hughes, having confessed subsequently to an interesting love life involving bisexuality. Of Ken Livingstone, Boris Johnson and Brian Paddick, though, it did seem that the incumbent mayor was the most improbable Lothario of the trio (and after all, he does have accusations of cronyism and allegations about an excessive fondness for the grape covered already).

Yet (Cecil) Parkinson's Law has struck again, in that it is always the one who seems the most implausible man about town who turns out to be it. The mayor has kept not one but two families a secret and has been candid only now because a book entitled, perhaps awkwardly in light of the facts, Ken: The Ups and Downs of Ken Livingstone was set to tell all. Mr Livingstone himself seems confident that the revelations would be of little concern to Londoners, asserting that nobody in the capital city is much “shocked” about sex unless it involves “children, animals or vegetables”. Until that remark, it had not been thought that London was a city in which a carrot could not exist without fear of being seduced by a politician.

The mayor is correct in asserting that voters are more tolerant on personal matters than they were. But in many regards the question is less about Mr Livingstone's multiple trysts than his failure to be honest. His comment also makes a curious assumption about modern urban values. The mayor might find this weird, but there are many people in London - Max Mosley not included - who aspire to a lifelong loyal and loving relationship that serves as a safe and stable environment for bringing up children. There will be voters who conclude that the mayor should have far more time to spend with his families.