Australia's prime minister has officially launched his conservative coalition's campaign less than a week before an election in an extraordinarily personal presentation.

Scott Morrison is his government's third prime minister in the administration's six years in office and still remains relatively unknown to many Australians. He is asking them for a third three-year term when they vote on Saturday next week.

The coalition's launch in the city of Melbourne on Sunday included recorded interviews with Morrison family members that covered his wife Jenny's diagnosis with endometriosis and their 14-year failed battle to conceive through IVF before having their two daughters naturally.

Morrison also outlined government policies including support for first-home buyers.