He said he would go to court to defend it if Mr Craig took it to that extent and Mr Craig's repeated recourse to lawyers to shut down criticism would have a "chilling effect" on free speech and political debate.
"All I would say to him is that in a democracy, in an open society, we have a free and frank exchange of views. It can be robust, but that's what we expect from our politicians. I don't want robust political debate to be chilled by the potential actions of defamation lawyers."
"Colin Craig now has a track record of making allegations of defamation if someone says something about his views that he does not like. I don't plan to back down from my statements because of a lawyer's letter. New Zealanders want to hear freely from their politicians. Colin Craig appears to want all our statements run past lawyers."
Dr Norman said he had not defamed Mr Craig. The comments were made in the context of a political speech and were obviously metaphors to illustrate an outdated view about women and gay people. He said Mr Craig's views "belong in 1950s New Zealand."
Mr Craig said he had taken the step of getting his lawyers to assess the claim and seek a retraction and apology because he believed the comments were inaccurate and were widely broadcast.
He said Dr Norman's comments did not reflect his views.
"I can't believe he would think [I believed] a woman's place is in the kitchen. If you look at our party policy and the way I've lived my life it's pretty clear our policy is that a woman should have choice. If they want to be in the home - and I would not limit that to the kitchen for a moment - they should have that option. If they want to be in the paid workforce they should have that option. It couldn't be more wrong."
He said his wife was an equal partner in his business and had worked with him in it for 15 years. "So I find it quite an offensive statement to think I might think these things, and certainly to publicise that nationally has gone too far."
He said he did not have a problem with homosexuality, although he had opposed changing the definition of marriage in the law to allow gay people to marry.
"We've made it very clear we think people have the freedom to choose and live whatever lifestyles. People are going to choose what they're going to choose. You can't take people and put them in some sort of closet."
The letter from Chapman Tripp "invites" Dr Norman to issue a retraction of the statements in a form which was likely to receive similar prominence on television.
"Neither the context of an election year nor the occasion of the Big Gay Out provide you with a licence to say anything you like about Mr Craig ....They are also defamatory as it harms [Craig's] reputation to say he holds such sexist, derogatory and offensive views about women and gay men."
Mr Craig said he was aware different rules applied to politicians under the Defamation Act and it was an election year, but said Mr Norman had couched his comments as statements of fact rather than opinion. He said if Dr Norman refused to apologise, he would consider taking it further including going to court.
"Our assessment is that it does cross the line. We set that standard that says things politicians say need to be more accurate, or express an opinion. It's a reasonably polite request, I think, and all we've asked for is a retraction and an apology."
Mr Craig is renowned for calling in his lawyers over comments made about him - satirist Ben Uffindel was a previous target after a blog post written about Mr Craig. Mr Craig said he had so far sent about six letters relating to defamatory statements and about two complaints to the Broadcasting Standards Authority. He said he had received apologies for each of them.
In December, TVNZ was required by the Broadcasting Standards Authority to issue an on air apology for an item on Seven Sharp about him.
