Vic leaders to vote 'yes' on gay equality

Victoria's political leaders say they will vote 'yes' in the marriage equality postal plebiscite, but Premier Daniel Andrews has labelled the $122 million poll a "colossal" waste of money.

Mr Andrews says he will vote yes if a ballot arrives at his house, but slammed the fact it was going ahead.

"It is a colossal waste of money; parliamentarians are paid well to make laws and change laws," he told reporters on Thursday.

"The act was changed to discriminate against same sex couples without a plebiscite - why do we need one that isn't even binding?"

Opposition Leader Matthew Guy says he will also vote yes.

"I'm going to vote in it, when it comes, I'll vote 'yes'," Mr Guy told reporters.

However, he did not think it was a waste of money because the government had to find a way to put the matter to rest.

"I, like I think the majority of Australians, want this issue over because to me it is straightforward," he said.