"It's on. A few moments ago I saw the governor-general and asked that she dissolve this parliament and call the federal election for September 7," Rudd said in an email to Labor party members. (Agencies)
"Australians now face a choice...And the choice couldn't be starker," Rudd was quoted as saying by the Australian Broadcasting Corporation.
Earlier, Rudd flew in to Canberra this afternoon to visit the Governor-General and formally ask Quentin Bryce to issue the writs for a poll.
The five-week campaign will see Rudd hoping to complete a comeback for the Labor Party after he first assumed the Prime Minister' office with his landslide victory over conservative leader John Howard in 2007 polls, which ended suddenly in mid-2010 when his Labor colleagues turned on him and voted in Gillard.
"The time has come for the Australian people to decide on our nation's future," he told the media after arriving back at Parliament House.
He now faces a conservative opposition led by Tony Abbott, a former minister in Howard's government, in the election which had to be held before November 30.
Rudd said Opposition Leader Tony Abbott will "bang on with some negativity" and has criticized him for not "having the ticker to debate his real agenda".
Labor will be vying to retain government after six years in office, dominated by leadership struggles and debate over its handling of multiple issues of climate change, asylum seekers, and the global financial crisis.
"It's on. A few moments ago I saw the governor-general and asked that she dissolve this parliament and call the federal election for September 7," Rudd said in an email to Labor party members.