The billboards are part of a campaign being run by the Opinion Partnership, whose address is listed as in Johnsonville.
Mr Ansell, who lives in the Wairarapa, says the billboards are a form of attack politics but the backlash from Nicky Hager's Dirty Politics book had not made backers reconsider running them.
"All round the world people say that attack advertising is horrible, and all around the world it works," says Mr Ansell.
"These are valid criticisms in a political system, not dirty politics," he says.
Information distributed by the Opinion Partnership says it is concerned about the influence the Green Party would have in a Labour-led coalition government.
Mr Ansell is one of three publicly declared members of the group.
The other two are former Federated Farmers president Owen Jennings and businessman John Third, of Johnsonville.
Mr Ansell says the campaign targets two types of voters, male blue collar workers who traditionally vote Labour and upper-middle class women who care about the environment.
In describing the kind of man the campaign is targeting, Mr Ansell quoted a letter to the editor which expressed disappointment in Labour's infiltration by "feminazis and pillow-biters" in a comment on Chris Trotter's left-wing blog.
Mr Ansell says he quoted this part of the letter because it is a good example of how his target audience speaks.
"They are down to earth, they use bad language and all the rest of it," he says.
He says he does not endorse the kind of language used in the quote.
"You're trying to beat that up into a smear on me," he says, "I'm just trying to find my market according to things I hear."
In contrast to Mr Ansell's comments, Mr Third says he does not think the billboards are a form of attack politics.
"Our objective is not attack politics, our objective is actually to stimulate some proper analysis of policy," he says.
Mr Third refused to answer questions about who was funding the Opinion Partnership and how much they were planning to spend on the campaign.
"That's really our business," he says.
Mr Third would not confirm or deny whether conservative Christian organisations had helped to fund the campaign.
"They may have but I'm not going to be declaring who."
The revelation that the Exclusive Brethren were funding an anti-Green campaign during the 2005 election was the basis for Nicky Hager's book The Hollow Men.