TONY Abbott's decision to wait until the Parliament had shut down at the end of last year before making it clear that he would block a conscience vote on any gay marriage bill could cost him in the long run.

It can be a mistake to decide how to vote on something you haven't even seen. Alexander Downer made this mistake as Liberal leader when he took the shadow cabinet to that famous hotbed of Liberalism otherwise known as Burnie in Tasmania. In their collective wisdom, they decided the party should vote against whatever bill then attorney-general Michael Lavarch produced to override Tasmania's anti-gay laws.

As a shadow minister at the time, I was given the task of talking and talking and talking until finally we could allow the bill through ''on the voices''. That is, everyone could say what they like on the record but when the vote came we Liberals had to remain silent and not call a division. It is a humiliating position for a great party.

But there is another problem. One of the things that really aggravates members of Parliament is when a leader announces, through the media, a decision that has been made after Parliament has risen. As there is no party-room meeting over the break, the leader's announcement and policy position gets all the airplay and permeates the public mind. MPs who disagree with the decision rightly see the timing as a tactic to weaken them