I've always advocated the "softly softly" approach myself
but what about some tricks from the Dick Smith playbook? Was Warren Truss under parliamentary privilege when he made those untruthful and defamatory statements reported in the Australian? Politicians just get used to lying, yet rarely seem to get called on it. A simple writ may get a LOT of press coverage, and help highlight the true position.
It depends on how hard you want to play, I guess.