Purnell also has the countenance and personality of a future leader - as the Spectator tipped last year. I hope he reconsiders his statement that he will not run in the leadership election which must surely follow before long.
Number Ten will surely brief that Purnell was weighed down by difficulties over his expenses, or deranged, or both. It won't matter. This is a serious man resigning for serious reasons. Others will follow tomorrow.
So: the moment of decision has arrived for the timorous Labour tribe. Alea iacta est.