Not knowing what the hell you are there for can disarm your opponent. Look at One Nation. Watch them squirm as you just sit there and wait for them to say something first.
Negative comments are for wusses.
It's funny how negotiations can change tone once you have made it clear to your opposite number that he is the boil-encrusted son of a nightsoil man with all the style and grace of a David Kemp beard. While stalling for time can be handy, even better is to waste time. Discuss your mother's illness, interrupt the meeting to clip your toenails, ask if anyone wants you to get them McDonald's for lunch. Discrediting associations is a good start, but go further. And when all else fails, change the law to suit you.