From the Register. They usually shoot pretty straight.
[While politicians] are a peculiar and varied breed, there are three things you can be fairly certain will not hold much sway with them:
Ideological argument. Politicians are nothing if not pragmatic. Their very survival is based on seeing which way the wind is blowing and adjusting accordingly
Little-man defence. Politicians will not risk upsetting rich and powerful people and companies unless there is a principle at stake: that principle being that the government ultimately decides. Therefore arguing a point on the basis that it will restrict or impair a powerful body is counterproductive
Criticism. Politicians do not respond well to criticism. In fact, the more they get, the more stubborn they become. Flattery is the surest route to their heart, and this means making them feel important. Wining and dining, listening, applauding their insight and then putting your point across