Australia's conservative prime minister has predicted a close result at elections on Saturday as his rival used a campaign rally to revel in the memory of one of his center-left party's greatest victories 47 years ago.

Prime Minister Scott Morrison made his final major speech of the campaign at the National Press Club in Canberra on Thursday with a recurring theme that now is not the time to elect a Labor Party government.

Labor leader Bill Shorten chose to make his final campaign pitch in the same western Sydney venue where party hero Gough Whitlam gave what has been remembered as his "It's Time" speech in 1972.

"It's Time" was also the campaign slogan. Weeks after his speech, Labor won its first federal election victory since 1946.