The former European Commissioner was appointed in November 2011 to lead an unelected right-left government of experts to save Italy from financial crisis after Silvio Berlusconi quit.
Mr Berlusconi's party withdrew its support for Mr Monti in December, and he resigned on December 21, about two months earlier than had been planned.
On Friday Mr Monti abandoned his mediator role to enter politics in his own right and lead a centrist alliance to fight the February 24-25 parliamentary vote.
The 69-year-old's bloc is now in a three-way race with the Democratic Party (PD) on the left and four-time prime minister Mr Berlusconi's People of Freedom (PDL) on the right.
Initial polls suggest Mr Mr Monti's bloc could gain up to 16% of the vote, depriving rivals of a clear win, but not enough to govern. They show the PD and its coalition ally are on track to win the vote, at least in the lower house. Mr Monti said he wanted to form a broad coalition of pro-Europe, pro-reform parties after the election.
To Italians, who have borne the brunt of austerity measures he introduced in late 2011 to save Italy from a Greek-style debt crisis, he promised to lower labour taxes and "redistribute" wealth from the richest to the poorest if he wins.
"We need to reduce taxes on the labour force, both on workers and companies," he said in a radio interview.
Mr Monti ridiculed Mr Berlusconi, 76, saying he was "confounded" by "illogical" swings from praising his government to attacking it. "I hope voters are less confused," he said.
For the first time he also directly attacked the centre-left, saying Pier Luigi Bersani's PD and its SEL ally were too close to labour union positions aimed at protecting jobs and not creating new ones.