During the close to five years that National has been in power, John Key and his colleagues have kept a very tight lid on any argument, dissent or splits within the Cabinet.
Internal tensions, friction between ministers or divisions over policy have been kept so hidden from public view that you would be hard pressed to come up with an example. Not yesterday, however.
Two senior ministers chose to break their silence - and break ranks in the process - in the full media glare of a meeting of Parliament's privileges committee.
Justice Minister Judith Collins and Police Minister Anne Tolley were in high dudgeon, making it abundantly clear they were less than impressed with the actions of the David Henry inquiry into the leaking of the report by Cabinet secretary Rebecca Kitteridge into the workings of the Government Communications Security Bureau.
The privileges committee has moved with commendable speed in launching a probe into the Henry inquiry - for which Key has responsibility - particularly its requests for assistance from Parliamentary Service in retrieving data detailing Dominion Post journalist Andrea Vance's phone logs and movements around the parliamentary complex.
Sad to say, however, that protecting press freedom does not seem to have been the committee's sole motive for acting in some haste.
That became evident during what was the first day of hearings with Henry being the first witness to appear. Collins and Tolley chose their words carefully. But there was obvious anger that Henry had obtained access to their email records and landline and cellphone logs without their express permission - an invasion of privacy that Collins described as "contemptuous" and a "chilling experience".
The pair rounded on Henry for not weighing up the constitutional implications of an informal inquiry rummaging through a minister's communications. As a former senior public servant, Henry - more than anyone - should have been aware of the need to tread very carefully.
That those communications would potentially be discoverable under the Official Information Act should have taken some wind out of the two ministers' billowing sails.
And Henry should not have been their only target. The Prime Minister's office told ministers to co-operate fully with the inquiry - and that Key expected nothing less. That effectively gave Henry much more muscle in his hunt for the leaker.
But then Collins and Tolley were also treading carefully yesterday. Key's response to their gripes was short and to the point.
The two ministers were entitled to their point of view. But he had approved the Henry inquiry's terms of reference. If any minister had a problem with those, they had been free to complain. But none had.
As for Henry, he was besieged by reporters as he left, having earlier found himself jousting once again with Winston Peters over another inquiry - the one in the 1990s when Henry was Commissioner of Inland Revenue and which dealt with the "Winebox "of tax evasion-related documents.