Mining billionaire Clive Palmer’s $400 billion-plus lawsuits against the Australian government top a list of liabilities tucked away in Tuesday’s budget papers along with the Brisbane Olympics, Papua New Guinea’s new NRL team, a struggling Australia Post and the bailouts of Rex Airlines and the Whyalla steelworks.

While Treasury officials do their best to forecast spending over the next four years, the statement of risks in the budget details tens of billions of dollars in exposure taxpayers could be forced to pay.