Chairman Carter, who has no vote, yesterday refused to confirm which way the battle lines were drawn, but he did confirm the board would continue to thrash out the issue before a full meeting next week.
Under the Blues' constitution a consensus decision, rather than a majority one, must be reached.
Carter said the division began at a board meeting on April 28 when Kirwan revealed the plan which he hoped would save his job.
The now infamous succession plan, revealed by the Herald, included Crusaders assistant Tabai Matson, who has since rejected Kirwan's offer.
It was the first board meeting attended by Wilsher and Edmonds, replacements for Maurice Trapp and Glenn Wahlstrom, who had to resign their positions once they were elected on to New Zealand Rugby's board.
Once Kirwan left the room the arguments started. "There was disagreement and it is fair to say things got a little bit heated," Carter said. "There were strongly held views and people were pretty upset about the way it transpired.
"It was the first meeting attended by the new board members and it was really unfortunate timing."
Carter, who said he was disappointed he had been unable to get the two parties to agree, added he felt there would be concessions this week.
"I am more confident than a week ago and the reason for that is that everyone can see the damage this saga is doing to the Blues.
"Everybody has the best interests of Auckland Rugby and the Blues at heart."
New Zealand Rugby boss Steve Tew said in a statement he had been in discussions with the Blues.
"As a consequence it is apparent there are some relationship issues among shareholders and we have offered to mediate," he said.
"We hope all parties will accept this offer so we can together resolve this issue. Because we are in the middle of discussions, we are unable to comment further at this time."
The very public dispute is the first since New Zealand Rugby's new franchise ownership model took effect in 2013. The new model allows for a 50 per cent ownership of the franchise licence by an investor, in the Blues' case Bolton.
When asked if this dispute proved the model was flawed, Carter said: "I don't think it shows a weakness in the model. It's just that when you have different directors around a table sometimes people have differences of opinion.
"It's not like a commercial board where a majority decision is enough; according to our constitution we have to have a consensus."