Labour MP Andrew Little says he won't be intimidated by threats of legal action from the ACC Minister, Judith Collins.
Ms Collins says she was defamed by Mr Little and his Labour colleague Trevor Mallard on Radio New Zealand in comments about who leaked details of ACC claimant Bronwyn Pullar to the media.
The minister's lawyers wrote to the two MPs on Thursday, saying they'd been instructed to begin proceedings.
Mr Little says he has replied saying he has no intention of cooperating and reminding them of the convention that sitting MPs cannot be served with legal papers at Parliament.
"I maintain the view that it is an act of bullying on Judith Collins' part. I'm very confident with the legal advice that I have received that my position is a good one, and I'm not going to be intimidated."
Andrew Little says Ms Collins is desperately trying not to lose face, but he's confident the case won't go to court.
Trevor Mallard says he has nothing for which he needs to apologise.
"Judith Collins' lawyer has written me another letter in which he says that he is going to issue proceedings - hasn't yet - and really it hasn't taken it on much from where we were two weeks ago and two weeks before that."
Mr Mallard says if Ms Collins' lawyers want to serve papers on him, he's not hard to find.
Radio New Zealand, which was previously threatened with legal action, has not yet received a letter.