A member of the Turnbull government has prepared a private members bill to introduce fixed, four-year terms to mend what he says is the one "glaring" structural weakness in our political system.

Liberal MP David Coleman argues the shift to four-year terms is necessary to give governments and citizens greater certainty. And he says "governments would get more done".

"A fixed, four-year term reduces the impact of short-term political drama, and allows for a more strategic approach to decision-making," he says.

"Economic activity would increase. Both businesses and consumers tend to hold off on investment during election periods - and the phony war that precedes them," and in addition, "consistency with the states would be achieved. Every state except Tasmania now has fixed four-year terms."