Labor has secured additional budget estimates hearings next year to put the blowtorch on government spending before Australia goes to the polls.
The upper house on Thursday passed a motion to scrap the Senate sitting two days after the April 2, 2019 budget and hold estimates hearings on April 4 and 5 instead.
Estimates gives senators a chance to question government ministers and bureaucrats about public spending ahead of the May election.
There will be further hearings between April 8 and 11 provided the government doesn't call an election before then.
Manager of Opposition Business in the Senate Jacinta Collins acknowledged the government usually had the right to set the parliamentary sitting calendar.
"This government has abused this right by manipulated the sitting calendar to suit its timetable for an election and it is clearly ducking for cover," Senator Collins told parliament on Thursday.
Cabinet minister Mitch Fifield urged senators to oppose Labor's changes, but they successfully changed the sitting calendar with the support of the Greens and a handful of crossbench MPs.
