If it had not happened now, it would have happened within the next few weeks.
If Labour was going to have a new leader - and David Shearer's exit from that post was inevitable - that person had to be well ensconced in that role before Labour's annual conference in early November and the Christchurch East byelection expected to be scheduled for later that month.
With the election of the new leader expected to take at least four weeks, time was becoming very much of the essence.
Shearer's resignation was inevitable because the great bulk of voters had typecast him as a weak leader.
Such a categorisation might have been unfair. But for all his positive attributes - intelligence, a fundamental decency, enthusiasm and ability to laugh at his own expense - the public only saw someone who sounded hesitant and uncertain.
When he tried to sound assertive, he sounded like he was trying to sound assertive. He only succeeded in sounding fake.
The public determined those failings as weakness. He could not convince even Labour voters to back him in the preferred prime minister ratings. There was no sign after 20 months as leader that Shearer could turn that perception of himself around.
The public had filed him alongside other Labour leaders who failed to cut it. He was another Bill Rowling, another Sir Geoffrey Palmer, another Phil Goff, another Arnold Nordmeyer rather than a David Lange, a Norm Kirk, a Helen Clark or a Michael Joseph Savage.
Once classified as being in the company of the former, Shearer was finished.