Phil Goff had better start looking over his shoulder. When it came to power, National was banking on six to 12 months of destabilisation in Labour as it feuded and fought over the leadership once Helen Clark left.
That failed to happen then, but it's starting now. It took just a couple of minor miscalculations by the Labour leader. His handling of some of the Richard Worth scandal stirred up internal party rumblings but these were muted by the need to maintain a united front for the Mt Albert byelection.
A stumble over the dole for all followed by the fiasco over Bruce Burgess, the unemployed man who was supposed to be the poster boy for Labour's dole plan who turned out to have two rental properties, and the anti-Goff movement is under way.
It is occurring in the blogosphere, and not on the traditional centre-right sites that love to lampoon Goff and Labour but on centre-left sites.
The Left's curmudgeonly commentator Chris Trotter fired the first shots on his site, Bowalley Road. Incensed at Goff's statements regarding socialism as a 19th-century doctrine rejected by modern Labour, Trotter blew a fuse. "If this is your view, Phil, that the quest for democratic socialism should be dismissed as something belonging to '19th-century history', then I say 'The hell with you'." Trotter tells Labour Party members: "Find yourselves a new leader."
Russell Brown's liberal-left Hard News offered Goff the pained advice, that if he "wants to float ideas, could he please ensure they don't have any holes in them when he pushes them out from the jetty".
If the commentary by the bloggers was hostile then many of the readers' comments were insulting enough to make a hardened talkback caller blush.
Some Labour MPs may choose to dismiss this small digital brushfire as the ravings of a few disaffected leftists but this kind of unrest can - and will - spread.
The blogosphere means we now hear what party supporters once said in private discussions over a beer. That the whingeing about Goff has started after a couple of small mistakes means there is a deep enmity to him on the left of the party and his opponents are beginning to gather steam.
He has done himself few favours with his media team in Parliament. With the Worth and Burgess stories, they held back from journalists material that didn't suit their case, thus earning a big black mark from the press gallery, with whom they desperately need a relationship of trust.
The debacle gave the Government a huge club with which to beat Labour. It allowed John Key to question Goff's judgment for using ordinary New Zealanders such as Burgess as political footballs without checking facts.
Goff was an intelligent and able Cabinet minister but now I hear Labour supporters wondering if that is enough to make him an Opposition leader capable of winning an election. Frankly, at this stage, there is no one better to lead the party.
Nevertheless, the knives are being sharpened and over the coming year the destabilisation of Goff is likely to intensify. This may not lead to his overthrow but it will ruin Labour's chances of presenting itself as a stable alternative government.
The most interesting part will be seeing who on the left will first raise their head to make a push for the leadership. As a great New Zealand thinker once said: "It won't happen overnight but it will happen."