Hard sell for budget 2018 already underway

Prime minister Malcolm Turnbull says families will get help with the cost of living, essential services will be guaranteed and road and rail projects will be rolled out in the budget tonight. Image: Scott Morrison and Mathias Cormann (AAP)

Personal tax cuts for low and middle-income earners are expected to be a feature of treasurer Scott Morrison's third budget, although it's unclear what form they'll take.