The shape of the remainder of the mayoral race came into sharper focus last week thanks to one conspicuous absence, one opinion poll and three supposedly “secret” children.

The absence was Boris Johnson’s from Time Out’s hustings at ULU on Wednesday, which Ken Livingstone, Sian Berry and Brian Paddick all attended. Why did The Blond not appear? That depends on whom you talk to. Time Out complained that it “bent over backwards” to accommodate Johnson, but Team Boris took a different view. Whatever the reason, his enemies claimed that Boris had bottled it, prompting the swift riposte that Ken has missed a few events too. What’s more, he looks like missing the NO2ID Cards hustings on 8th April and the Tory Centre for Social Justice’s on 16th April.

Both sides claim full diaries are the problem, but suspicions remain that at this stage of the race both frontrunners are keen to dodge hostile crowds. Londonist offers no judgement other than to note that doing so appears consistent with both candidates now concentrating hard on those voters most likely to favour them. Johnson continues trekking from suburb to suburb, sprinkling his special brand of stardust. Livingstone has been displaying his radical credentials in Islington, bashing the BNP in Holloway on Friday and doing an anti-war walkabout in the Angel this morning.

The opinion poll gave a strong clue to why. Compiled by ICM for The Guardian and published on Wednesday it told a very different story from YouGov’s for the Standard on Monday, giving Johnson only the narrowest of leads. The details indicate strong polarisation, with Boris’s fanciers slightly more certain of voting than Ken’s. Poor Brian Paddick is getting squeezed as a result. And then, of course, came the revelations that as well as the two children he has from his present relationship, Livingstone has three children from previous ones. This – surprise, surprise – has excited the majority of newspapers far more than Johnson’s disclosure to Marie Claire that he did dope and coke during his youth. Londonist doubts if any of this will make a big difference either way, though a small one might be crucial to the result.

By Dave Hill

Read more from Dave over at the Guardian, and on his mayoral blog.