So, when it became clear that a majority of MPs were going to support a ban on smoking in cars carrying children, what did Dave and Boris do?
They jumped on the fast-moving bandwagon.
Writing in today's Telegraph the Mayor of London wrote, 'Banning smoking in cars is bizarre, intrusive – and right'.
Needless to say Boris's words are everywhere, at home and abroad, just as he intended:
Boris Johnson backs bid to ban smoking in cars(ITV News)
Boris backs ban on smoking with child in car (Sky News)
London Mayor Boris backs smoking ban in cars (AFP)
To the best of my knowledge Boris has never commented on this subject before. To call it opportunistic is an understatement.
You might have thought David Cameron would see an opportunity to demonstrate some backbone and stick to his belief that legislation was a step too far.
Not a bit of it.
Within hours the PM had thrown the towel in and joined the dream team of Luciana Berger, Michael Gove, Boris Johnson and virtually every Labour MP:
David Cameron backs smoking ban n cars carrying children (Guardian)
You couldn't make it up.
Meanwhile, like King Canute, I continue to drag myself from one London studio to another ...