Prime Minister Scott Morrison has locked in a May election, with government sources saying the Coalition needs to deliver a budget to complete its economic story before going to the polls.

On Sunday, Mr Morrison guaranteed Parliament would return in February, despite the prospect of another challenge to the government’s grip on the lower house of the kind it narrowly avoided last week.

In doing so, he effectively quashed speculation that he could bring forward the election to March. Senior government sources confirmed there was no serious discussion about March, leaving May 11 or 18 as the possible dates.

Asked during a press conference on Sunday whether he could guarantee Parliament would sit again before the election, Mr Morrison said: “Yes.”