A smiling but silent Ms Gillard left her suburban Melbourne home just after 7am (9am NZT) and is expected to arrive in Canberra about 9am.
Shortly after that, she is likely to call on Governor-General Quentin Bryce at Government House to seek permission to call the election -- tipped to be either August 21 or 28.
The coalition needs to win an extra 17 seats - or a swing of 2.3 per cent - to get back into government just one term after Kevin Rudd ousted John Howard's government after 11 and a half years.
But Mr Rudd was rolled by Ms Gillard just three weeks ago, and Ms Gillard has not experienced the expected honeymoon, despite resolving the mining tax controversy.
Opposition Leader Tony Abbott is in Queensland - a vital state for both parties - and has already flagged the removal of Work Choices, one of the biggest threats to the coalition's chances of election.
The surprise move by Mr Abbott will be a blow for Labor, which has been using industrial relations as a key weapon against the coalition.
In a speech to the Liberal National Party conference in Queensland on Saturday morning, Mr Abbott will announce that a coalition government will work within the existing workplace laws introduced by Labor.
"Yesterday the shadow cabinet backed my recommendation that an incoming coalition government would not seek to change the Fair Work Act at least for the three years of the next term of parliament," he will say.
Ms Gillard, who on Friday finished her tour of all Australia states and territories in Tasmania, was giving nothing away about an election date.
But she sent a Twitter message urging people make sure they are enrolled to vote.
"Don't miss out on your chance to have a say in our future. Go to www.aec.gov.au JG Senior MPs from both Labor and the Liberal on Friday night warmed up for the campaign."
Two senior MPs from both sides did warm up for the campaign on ABC Television late on Friday night.
Agriculture and Sustainable Population Minister Tony Burke was spruiking the government's economic credentials.
"There will be one nation in three years time that's moved into surplus - it'll be Australia," he said.
"The economic record is deeply impressive."
Opposition frontbencher Christopher Pyne countered, by saying Australians had been better off under the Coalition.
"(Labor will) run a very negative campaign against Tony Abbott because they have no record to talk about."
