Mr Craig had given Dr Norman a deadline to apologise over comments he made in a speech at the Big Gay Out, but Dr Norman refused to do so.
Dr Norman had described Mr Craig as someone who "thinks a woman's place is in the kitchen and a gay man's place is in the closet".
Mr Craig now says he'll continue pursuing a claim against Dr Norman for his 'woman's place' comment, but his 'gay man's place' claim is on the back-burner for now.
"After extensive discussion and advice from my legal team, I've decided to proceed immediately against [Dr] Norman regarding his claims about the place of women."
He said he would not immediately pursue Dr Norman's comments about gays because his lawyers had already indicated discovery would include emails and other correspondence.
"Given the extensive debate around the redefinition of marriage, this is many hundreds, if not thousands of documents, and would result in prohibitive costs and time delays.
"It is hoped by breaking the case into two stages, that a declaration of defamation may be obtained prior to the election this year."
Asked if he would apologise, Dr Norman told Radio New Zealand this morning he had been pretty clear about standing up against discrimination.
"If Mr Craig intends to continue with it [the defamation case] then so be it. But from my point of view, what's important is to stand up for a tolerant, inclusive New Zealand.
"The only way we'll get a tolerant, inclusive New Zealand is if we stand up against intolerance."
Prime Minister John Key indicated he believed Mr Craig needed to harden up.
"If Mr Craig is going to be part of the Parliamentary process to be honest he's going to have to get used to a lot more rough and tumble than he's currently demonstrating.
"We all learn to develop a thicker skin as we spend our time here. The reality is this is the nature of Parliament."
Mr Key repeated his advice last week to his potential minor party allies including Mr Craig and Act Leader Jamie Whyte: "In the end, I think New Zealanders are interested in the issues that matter. People get up in the morning concerned about their jobs, their children, their health, their families, the communities they live in not whether Elvis is still alive, man walked on the moon or whether Russel Norman might have a view about what Colin Craig things about certain issues."
