Even when they are not actually co-ordinating their attacks, they appear to be working together.
Shearer, Norman and Peters have inflicted damage on the reputation of Prime Minister John Key through a combination of the SkyCity, John Banks, Kim Dotcom and GCSB sagas.
Few people believe John Key is actually dishonest but more people now believe he is too casual, too trusting of departments, too sloppy in his oversight and too forgetful.
Co-operation between Labour, the Greens and NZ First was reinforced yesterday at a union-organised jobs summit in Auckland, where the three leaders launched an inquiry into manufacturing that a select committee denied them. The symbolism of teaming up now, with the Government looking as weak as it does, was powerful.
The manufacturing inquiry builds on the co-operation the parties have already had this term over the sales of the Crafar farms, the "Keep Our Assets" coalition and reform of monetary policy.
Times have changed since the 2005 election, when Peters refused to deal with Labour unless the Greens were kept out of government.
The Greens suspect that Peters' ill-will of the past was caused by a conference speech by the late Rod Donald in 2005 where he called Peters a snake-oil merchant and associated NZ First's policies to those of Hitler.
Peters went on to become a quite credible Minister of Foreign Affairs, leaving the Greens humiliated for the third time to be left out of government by Labour.
Peters may have residual resentment in the fact that Russel Norman supported the privileges committee censure of him in 2008 over his failure to declare that Owen Glenn paid his legal fees to the tune of $100,000. But it doesn't show. The Greens, like most in the Parliament, have some respect for his comeback and there has barely been a harsh word between them all term.
Whatever else the Roy Morgan poll does for creating perceptions of an alternative government, at the very least it should dampen the dormant hopes of the Cunliffe camp in Labour. With Shearer looking like a viable Prime Minister, the rationale for a replacement disappears. To be really safe he needs to take the party to at least 35 per cent and it is already evident this week that he will take more of the TV spots from spokesmen for greater exposure.
One poll does not an alternative government make, but there is another tomorrow, a TV3 poll, that will be watched intently for a continuation of the trend. Even if the numbers are not unequivocal for the Labour/Green/NZ First triumvirate, several polls in recent months have had the Maori Party or NZ First holding the balance of power.
Peters will resist being too closely coupled with the left, as he did yesterday with a suggestion that the co-operation over the inquiry might be extended to other areas.
But the fact is that he had a largely trusting relationship with Labour in government and the prospect of NZ First going with National for a third term seems slim.
Ultimately, that would depend on what deals National or Labour offer in the way of positions or policy concessions.
Before the first MMP government was formed in 1996, when NZ First settled on coalition with National and Peters being Treasurer, one of his negotiators tested the possibility of a power-sharing arrangement with Labour that would have made Peters Prime Minister for part of the term of government. Labour refused and the rest is history. Peters was 51 then; he is now 67, more experienced, and more realistic.
Labour is assuming he would like to reclaim Foreign Affairs if the numbers allow it at the next election.
The House resumes next Tuesday after a two-week recess, and the Opposition will already be starting on the front foot. Key's first task will be to correct an earlier answer he gave about having had no briefing about the GCSB's role in the Dotcom raid until September 17.
That the issue is adding to the strain on the Government's credibility is not lost on his own supporters. National Party pollster and commentator David Farrar said on his Kiwiblog this week that the Roy Morgan poll was sober news for National and set out a series of steps needed to recover, including a commission of inquiry into the GCSB - which the Opposition has been demanding - fixing the Christchurch schools debacle, and responding better to the child poverty campaign.
But the greater damage to Key's credibility has been about his political ethics. As a prospective Prime Minister in 2008, Key set a new ethical standard when he said he would not work with Peters, even forgoing government, because Key could not trust him. He held that position in 2011.
He slagged off Helen Clark for sticking by Peters through the political donation sagas. But when Key defended Act leader John Banks this year and refused to read a police report on donations that may have cast doubt on his trust of Banks, it became clear that Key's ethics were as impure as the next person's.
Having earlier taken the moral high ground, his fall has been harder. That also makes it harder to recover.