Government ministers and MPs believe May 14 or May 21 are the most likely dates for the federal election with the budget the last chance for a reset, after a summer defined by surging coronavirus cases, testing shortages and the deportation of Novak Djokovic.

As a new opinion poll showed the Coalition’s primary vote support lagging Labor as voters marked down Mr Morrison’s pandemic management, anti-vaxxer backbencher George Christensen caused fresh embarrassment for the government after publishing a podcast with a doctor urging parents not to vaccinate their children.