The WA Liberal spoke out about the issue at the University of Melbourne on Thursday night while accepting an award for his work to get same-sex marriage through parliament.

But Senator Smith also used the inaugural McKinnon Political Leader of the Year prize to lay out his next mission, fixing WA's share of GST.

"The issue of GST is corrosive on our federation," he said.

"The idea of a Commonwealth, where all states are treated equally, is being lost because of an agreement that is no longer working as it was intended."

He also called on both Liberal and Labor to commit to a Senate committee on the GST issue, beginning after the next federal election expected in 2019.

"By addressing the GST in the context of broader federal-state financial relations, we can lift it above the win-lose lens that often characterises changes in our national tax arrangements," Senator Smith added.

WA currently receives about 34 cents of every dollar of GST revenue it raises, while the other states and territories receive close to $1.

Under changes to the GST being looked at by the Productivity Commission, all states and territories would lose money except WA.

A final report on GST reform is due in May.

Australian Associated Press