Unity is everything, PM reminds WA MPs

Malcolm Turnbull has praised West Australian Premier Colin Barnett as he faces a test to his leadership.

Ahead of an unexpected spill on Tuesday morning AEST, the prime minister reminded MPs unity is everything in politics.

"Colin Barnett is and has been for eight years an outstanding member for Western Australia and while the decisions of his party room are decisions for its members they all understand what a great leader he's been, what he offers and will continue to offer to the West Australian people," Mr Turnbull told reporters on the floor of the New York Stock Exchange.