KEY POINTS:
It's rare National gets the treat of rubbing Michael Cullen's nose in a blatant contradiction, but finally it had some ammunition in the form of the great "trio of hongi" scandal.
Its moment came with last week's signing of the Tuhoe Treaty of Waitangi terms of negotiation, where
Dr Cullen and activist Tame Iti exchanged hongi on three occasions.
Labour's Trevor Mallard was unremitting in his criticism after Mr Iti's and National leader John Key's hongi on Waitangi Day, so yesterday Gerry Brownlee was out for revenge.
He reminded Dr Cullen that Mr Mallard had expressed disbelief at Mr Key's "endorsement" of Mr Iti, who was facing arms charges after the terror raids, and accused Dr Cullen of "not just one hongi, but in fact a trio of hongi".
Dr Cullen knew it was coming and restricted himself to noting that "as [Mr Brownlee] will find out sooner or later in his life, after the first time it is much easier".
Mr Brownlee wasn't done. Mr Mallard had said of Mr Key that "any decent leader would have had the backbone to turn around, go the other way and not greet Mr Iti". Now Dr Cullen must tell the public whether his "trio of hongi" meant he also lacked backbone because he had not taken the advice of "his wise colleague".
Dr Cullen retorted by noting Mr Key had only greeted Mr Iti because he had no other friends at the time. Dr Cullen, however, was at a formal powhiri and to decline the hongi would have been grossly discourteous.
At this, Mr Brownlee asked Dr Cullen if he now intended to apologise to Mr Key for such behaviour.
Given that Mr Key had been graced that very morning with an embarrassing apology from Bill English for loose lips at the party's conference, Dr Cullen swooped for the kill.
"There is only one deputy leader in this House who needs to apologise to Mr Key every day, and it's not me."
This launched Mr Brownlee into a tirade. The trio of hongi - now truncated by Labour's Dover Samuels to a "tongi" - was just the tip of the iceberg representing "one standard for Labour and another standard for everyone else".
In case anyone still doubted by this stage that Dr Cullen was guilty of the trio of hongi, he sought leave to table a "very fetching photo" of the pair.
Dr Cullen was happy to allow it, with one assurance - "that I will not have a question from Mr English tomorrow claiming the photo is an advertisement under the Electoral Finance Act".