A former New Zealand First MP is criticising his leader Winston Peters' handling of events last year, just as Mr Peters issued apologies to party members.
In a letter seeking membership renewals, Mr Peters says "sorry" for past mistakes and that "we acknowledge we made mistakes".
The party missed out on getting back into Parliament following a tumultuous year and election campaign in which Mr Peters faced scrutiny over party donations.
His former deputy leader Peter Brown says most of the mistakes were made by Mr Peters himself.
"Many of us knew that we were going down the wrong track in various areas, and tried to keep it on track, but we were all overlooked and over-ridden, and what have you, and as a result we didn't get an MP back in Parliament. It was a huge disappointment to quite a lot of people."
Mr Peters has not returned calls on the comments.
Letter 'focuses' on future
Party president George Groombridge says Mr Peters' letter is focused on the future.
Mr Peters says in the letter that before a new beginning is made "we want to use the hardest word in the English language - sorry".
Mr Groombridge says the letter is not "grovelling" but acknowledges mistakes.
"Our eyes were taken off the ball, that's what it amounted to, and that did not help us as a party because we moved away from policy and we were continually trying to defend allegations which really came to nothing in the long run."
Mr Groombridge says whether Mr Peters remains leader will be known after the party's AGM at the end of August.
Radio New Zealand News political staff say the letter may indicate Mr Peters is preparing to revive the party for the next election.