Yesterday, the Herald reported that party president Peter Goodfellow had emailed members saying a review into the party's disastrous election campaign found "the disunity, leaks and poor behaviour" were the key factors in that result.
The Herald was told the report was so brutal that some believed even the MPs should not be shown it in full.
Meanwhile, Stuff reported that sources "familiar with the report" say its recommendations include term limits on the board.
Newshub reported that Goodfellow had said the report was not published online as it would "give our political opponents the much-needed distraction".
Pressed on the issue of the report leaking, Collins would only say it was a "very full and frank review".
"It's a very thorough review, it's very hard-hitting and it's something we all, in the party, will be learning from," she said this morning.
But the review itself was commissioned and prepared for National's board, Collins said – "not MPs".
The fact MPs were allowed to read it was a "good concession by the board to MPs".
She said there was nothing in the report that MPs would be "that surprised about".
"But they will all find that it is a challenging and difficult document to read and it is one that is good for us as MPs to read."
But the document won't be available publicly, she said, as that would be a "distraction from the things that really matter".
