Now that David Shearer no longer has to worry about a knife being plunged into his back - at least not for a while - he needs to tackle another longer-running attempted putsch of a very different but equally serious kind.
Along with other colleagues, the Labour leader is getting increasingly perturbed by the ever more brazen campaign by the Greens to try to displace Labour as the major party on the centre-left.
The worry is not that the Greens might succeed. As last weekend's two television-sponsored polls showed, Labour is still the default option when swing voters tire of National.
The worry is that the Greens' behaviour risks working against both parties' wider interests in defeating National in 2014 and securing the keys to the Beehive.
Despite putting in a stellar performance in 2012, the Greens are averaging around 12.5 per cent in all polls - only marginally above their showing at last year's election.
In contrast, Labour is now averaging 33 per cent, compared with 27 per cent at the election.
The Greens' objective is to shift those ratios more in their favour. But the reality is that the party is having to put in an awful lot of effort just to stand still.
If anything, the Greens ought to be disappointed by the latest round of polls, including the Fairfax poll released yesterday which had them a shade over 10%. The have sought centre stage over a number of issues; could it be that last year's election result is as high as the Greens will get?
Armstrong continues, but unlike a number of commenters he doesn't ignore the elephant in the room, the Greens' financial policies:
That is partly why Labour had been relatively relaxed about being pinged by the Greens. Labour's muted reaction, however, seems to have only encouraged the Greens to further test the limits of Labour's patience - the latest example being an incendiary opinion piece in last Monday's Herald written by Greens co-leader Russel Norman.
The previous day's polls threw such articles into sharp relief by indicating that a Labour-Greens governing coalition was now a distinct possibility in the next Parliament. It is not the first time such an outcome has been picked up by pollsters. But it is the first time such a result has been registered by the One News-Colmar Brunton poll or the 3 News-Reid Research survey and thereby conveyed to a mass audience.
Labour was consequently aghast at Norman's subsequent announcement that he was angling for job of Minister of Finance in any Labour-Greens coalition formed after the 2014 election.
Labour saw Norman's intervention as poor judgment and a ham-fisted grab for power when the occasion cried out for both parties to show some decorum and highlight the many ways they could work together in the national interest.
Shearer immediately ruled out any prospect of Norman getting the senior finance role, saying that would go to David Parker, Labour's finance spokesman.
It is worth noting Norman did not make installing him ahead of Parker as a bottom-line.
It is more likely to have been an opening bid for post-election negotiations - one which the Greens could trade off in return for concessions from Labour elsewhere.
But the damage has been done. The thought that the Greens might be given even a junior finance role - as would seem likely - is enough to give many voters the heebie-jeebies.
Such an eventuality requires voters to be slowly acclimatised well in advance of it happening. Handed a political gift, National spent the week revelling in telling all and sundry that Norman had appointed himself to the senior role.
The episode has also left the hugely negative impression that at the first sign of a turn in the polls in their favour, the two parties were immediately squabbling over the perks of office.
We like that; the thought of the Greens getting anywhere close to finance "is enough to give many voters the heebie-jeebies". The Greens may not like the mining and oil industries, but they would certainly give the printing industry a shot in the arm!
Then Armstrong joins Chris Trotter in giving the Greens a word of warning:
In the Greens' defence, their efforts to push their vote past the 15 per cent level are not just guided by what they can screw out of Labour in coalition-formation deliberations.
They have also watched a succession of other minor parties being destroyed by participating in or propping up Governments.
Sniping at the Government of the day from the Opposition benches is one thing. Working collaboratively with a senior coalition partner to pass policies driven in the main by the senior partner is another thing again. That is the political reality that the Greens will face in government, should they ever get there.
And all the while, David Shearer will be looking over one shoulder for signs of BBQ's firing up in Herne Bay, and over the other for more snipes from Russel Norman and Metiria Turei as they try to position the Greens for a greater level of influence than they may merit. It doesn't get any easier for Mr Shearer.