National's Nick Smith has not been shy in the debating chamber this week in his assessment of the secretive New Zealand First Foundation.
Now he's received an email from Winston Peters' lawyer Brian Henry - a trustee of the Foundation - threatening legal action with potential damages as high as $30 million.
In the letter, Mr Henry invites Dr Smith - as well as the National leader Simon Bridges - to either apologise or repeat the comments outside the House without the protection of parliamentary privilege.