Australians should know when they are heading to the ballot box by the end of the weekend.
There are only two Saturdays left for an election to be held, May 14 or May 21.
But if the prime minister does not visit the governor-general by this Sunday it will rule out the earlier date, as a minimum of 33 days are required between calling an election and polling day.
It will also mean MPs will have to return to Canberra for the week as the House of Representatives is due to sit.
A program for the scheduled sitting was released on Friday afternoon but it is not expected to go ahead.
Mr Morrison says his visit to Governor-General David Hurley is not far away.
"Electoral terms are for three years. The last election was on May 18 (2019) and the next election will be held about the same time," he told reporters on Friday.
"You'll know very soon."
A potential hurdle delaying Mr Morrison from calling the election was cleared on Friday afternoon when the High Court threw out a challenge to his pick of candidates for several NSW seats.
Chief Justice Susan Kiefel said there were "insufficient prospects of success" to warrant leave for former Liberal member Matthew Camenzuli to challenge Mr Morrison's intervention in the state's local branches.
Meanwhile, Opposition Leader Anthony Albanese accused the prime minister of delaying the election so the government could continue using taxpayer funds to pay for advertising.
"Call the election, let the Australian people decide," he said on Friday.
"I feel like putting in a phone call to the prime minister if he doesn't know where the governor-general lives, and offer him a lift."
The prime minister is expected to call the election on Sunday.
Images: AAP & ALP