Prime Minister John Key doesn't "give a toss" about former National Party advisers John Ansell's inflammatory advertisements for coalition partners Act or Mr Ansell's even more controversial race based comments which followed.

Mr Ansell, famous as the brains behind National's 2005 iwi/kiwi campaign, resigned from his role as Act's marketing director over the weekend following howls of outrage over an advertisement in the Herald accusing the National Government of pandering to Maori radicals.

Mr Ansell went on to make further, even more vehement, criticisms of National and Mr Key on website Kiwiblog.

ACT's ads featured the Maori sovereignty flag headlined "Fed up with pandering to Maori Radicals?" It listed what ACT saw as National Party concessions to Maori. These ranged from the foreshore legislation to the spelling of Whanganui.

"Now is the time to draw a line in the sand. Only one thing can stop the Maori radicalisation of New Zealand. And that's a strong ACT," the ad concluded.

ACT leader Don Brash is standing by the ad but his marketing director Mr Ansell resigned because he thinks the party is made up of "cowards" who want key messages watered down.

This morning, Mr Key told reporters there was nothing new in either the Act advertisement - which was "factually incorrect" or Mr Ansell's subsequent comments and he was not bothered by them.

"What happens with him and the Act Party, frankly I don't give a toss about, but at the end of the day I don't think any of us would be surprised that he's making those comments."

He said the comments would not sour National's relationship with ACT.

"We don't share all the views that ACT quite clearly has but that doesn't mean we can't work with them, but we clearly don't share all the views the Maori Party has either but we've certainly proved over the last three years that we can work with them as well."

Mr Key said the advert and comments would not affect National's intentions regarding the Epsom electorate where it has essentially allowed ACT to win a seat, giving it a presence in parliament.

He said Mr Ansell's personal attacks on him as a "weak", "lily livered" Prime Minister who was in thrall to Maori interests at the expense of other New Zealanders were "not worthy of a response".

PM should not accept 'racist' Act ads - Greens

The Green Party earlier today asked for answers from Mr Key over its coalition partner's ads.

"They're his coalition partner, does he support the racist campaign they are running?" party leader Russel Norman asked NZPA.

"The Prime Minister speaks on behalf of all New Zealanders, and the vast majority of New Zealanders are not racists and are very uncomfortable with what ACT is up to and I think it essential he condemn this kind of racist campaign."

Dr Norman said the campaign was "old school Maori bashing. It's a desperate ploy by a failing party to try restart the race debate all over again".

Mr Ansell was behind a series of race-based billboards in the 2005 general election which Dr Brash narrowly lost as National's leader.

He was recently involved in billboards against new foreshore and seabed legislation for lobby group the Coastal Coalition.

Over the weekend Maori Party co-leader Tariana Turia attacked the ads as deeply offensive and fellow leader Pita Sharples said the ad was sad and disturbing, and its views inaccurate.

"You once again bring the Maori peoples' aspirations into contempt and ridicule."

Mana Party leader Hone Harawira, who left the Maori Party over its backing of National, said the ad was a "pathetic attempt" to rekindle racial politics.

"Your attempts to booster ACT in the polls by riding on the xenophobic fears of Joe Bloggs in the street will not work this time round."

Dr Brash rejected the accusation.

"The racial tension is there now, there are a great number of people throughout the country who resent the fact that successive governments have created legal preference for Maori," he told NZPA.

"We are simply reciting the fact that the National Government has continued a policy which Labour began."

The Maori Party's response was "entirely predictable", he said.

"My concern is that successive government have been willing to appease the Maori Party and other Maori radicals by adopting policies clearly contrary to what was intended in the Treaty of Waitangi."

The Weekend Herald newspaper published the ad, but The Dominion Post refused and ran a different version.

Dr Brash said that was a freedom of speech issue and the ad was a "recitation of factual statements".