Maori Party co-leader Pita Sharples has rejected claims the party leaders were undermined, and defended his maverick MP Hone Harawira after letting him off with an apology.

Mr Harawira yesterday apologised again to the nation for comments he made in an email almost a month ago, referring to Pakeha as "white motherf****ers", which prompted hundreds of complaints to the Race Relations Commissioner.

He will also stay in his electorate rather than attend the final fortnight of Parliament following the drawn-out process of defending himself against calls to stand down from the Maori Party.

However, he escaped serious censure and was welcomed back into the caucus yesterday at a press conference.

Labour leader Phil Goff said the lack of any real sanction showed the Maori Party leaders had been "rolled" by Mr Harawira after their earlier strong statements suggesting he resign from the party. He said the incident exposed serious rifts within the party which had not disappeared.

He also said Mr Harawira's extra time-out from Parliament was not real punishment. "Most of us would love to be sent back to our electorate for the summer."

Dr Sharples denied the leaders had lost the battle, saying they had never wanted Mr Harawira to leave the party. The request that Mr Harawira become an independent was to drive home that he also had responsibilities to the country and the Maori Party - not just his own electorate.

Dr Sharples believed an apology with no further censure was appropriate. However, he acknowledged that if the bad behaviour continued it would impact on the Maori Party's chances to get critical policies through.

"We are not into punishment. But quite clearly, if any MP is continually offending against the public, then the electorate has to think very seriously about his position."

In his apology, Mr Harawira said he had let down young people by setting a bad example as a leader. He also acknowledged he had derailed much of the goodwill the Maori Party had fostered over the past four years.

He said his email comments were "insensitive, hurtful, and unnecessary" and apologised to both Pakeha and Maori for the grief and anguish caused.

Neither Mr Key nor Mr Goff would say whether he considered the apology to be sincere.

Mr Key said the email comments were "racist, hurtful and have set back race relations in New Zealand".

"All of those things are regrettable. It's now up to Hone Harawira to prove to the New Zealand public that he meant his apology and that he can change his ways."

Dr Sharples defended the MP, saying it was Mr Harawira's "style" to be up front and "push the envelope publicly".

"If it wasn't for some of those heavy demonstrations in the past, we wouldn't be able to have moderates come along later on and push the same ideas politely and get them through."

He doubted any hits to Mr Harawira's credibility would make him ineffective because he would be working mainly with Maori communities.

"Maori are a forgiving people, and a lot of the work he'll be doing will be among Maori."

Mr Harawira's actions had "tested" the caucus but not damaged it.

"It's almost fortunate this has happened so we can see where our boundaries are and our behaviour patterns."

He conceded the process in dealing with the issue was not ideal and the party had some soul searching to do.

Mr Harawira's apology and return to caucus followed a meeting with caucus colleagues and party president Whatarangi Winiata on Tuesday that went on until midnight.

Mr Harawira was supported by wife Hilda, mother Titewhai and electorate chairwoman Rahuia Kapa.

Former Act MP Donna Awatere Huata also attended, and lawyer Moana Jackson acted as a mediator.