Act Party leader Don Brash has apologised to John Banks for not consulting him before his speech in which he proposed decriminalising cannabis.
Dr Brash said he did not regret making the comments but did regret not informing his party's Epsom candidate, Mr Banks, beforehand.
"I handled it in a discourteous way with John Banks. I've apologised to him for that."
Dr Brash voiced his personal support for decriminalisation in a speech about Act's law and order policy last weekend. Although he made it clear it was a personal view rather than party policy, it prompted a strong reaction from Mr Banks, a former police minister and hardliner on law and order, raising speculation of a rift.
Asked if he would have refrained from the comments at Mr Banks' request, Dr Brash said he would have at least made it clear Mr Banks was strongly opposed. He admitted he had blindsided Mr Banks - although he had told Mr Banks he would talk about cannabis, he had not given any detail.
Dr Brash will meet Act's board again this weekend and expected the matter to be raised because the board would be reviewing the broader law and order policy.
It is understood the board had raised the issue with Dr Brash the day before his speech, asking if it was a wise move and telling him to inform Mr Banks.
One party source said although the proposal might not be too unpopular, the manner Dr Brash raised it in had been "bizarre". The Herald understands some in the party have suggested Dr Brash be assigned a minder or have future speeches and proposals vetted.
Dr Brash did not believe he had damaged Act's brand, saying the party had a strong streak of social liberalism and always looked at new ideas. His decision to raise the issue was prompted by discussions with Act members.
However, he said it was possible his own brand was damaged because people viewed him primarily as an expert on the economy.
He had been widely ridiculed for promoting decriminalisation.
"No one enjoys that. That's because people don't know me. On many social issues I'm at the liberal end of the scale. There's a longstanding tradition within the Act Party of people being socially liberal."
He did not intend to raise the matter during the election campaign, saying it would detract from Act's main messages on the economy.
But several people had stopped him in the street to say decriminalisation was a worthwhile proposal, and he was amused by some of the commentary.
"People were wondering if Nandor was my secret love child or something," he said.
Party president Chris Simmons, who was not at last weekend's board meeting, said Dr Brash's view was not party policy, but the party was there to challenge the status quo.
He said there had been mixed feedback from party members since the speech.