Bill Shorten goes into the final day of this federal election with good reason to believe he can emerge on Saturday night as the next Prime Minister of Australia.

Yet Scott Morrison has fought so hard, and so cleverly, that he still has a chance to hold power.

Morrison raced through Queensland on Friday like a man who could not afford to rest for a moment. He chose a defensive strategy to shore up support in seats the Coalition already holds, like Leichhardt in the state's far north. Only one visit, to Herbert, was to a seat he might wrest from Labor.

Shorten campaigned differently on Friday to mark the passing of Bob Hawke - an event that has clearly motivated Labor Party members to fight even harder for victory.

The change of plan meant Shorten did not fly north as he had intended, so he could campaign in the seat of Forde in the southern suburbs of Brisbane, a Liberal seat that Labor believes it can win. He travelled from Sydney to Melbourne instead.

The latest Ipsos analysis shows that Labor is ahead of the Coalition in each of the key states, but it also shows that the gap is not as great at the end of the campaign as it was in the past.

Morrison's team believes the race is still incredibly tight in electorates like Corangamite in Victoria, Reid and Gilmore in NSW.

Shorten's advisers are more confident the numbers are falling their way. They target 20 seats, aiming to win 16 from the Liberals and defend 4 of their own, and estimate they will win enough to hold government.

Voters chose a hung Parliament after the Labor leadership coup of 2010 and gave the government a majority of one after the Liberal leadership coup of 2015, so history shows a narrow result is quite possible after the chaotic removal of Malcolm Turnbull last August.

Shorten has the advantage in most scenarios.

First, he has kept his lead in the polls for months before the election, much like Kevin Rudd did in 2007. No matter what Morrison has tried to do, he has not turned the tables.

Second, Shorten has a headstart. The redistribution in Victoria means Labor is notionally ahead in Dunkley, Corangamite and the new seat of Fraser, according to ABC election analyst Antony Green.

The third factor is the crossbench. If there is a hung Parliament, several of the existing and potential independent MPs are on record saying climate change is a factor in any decision on which party they would support. This may work in Shorten's favour if he has to negotiate support.