The SDP chief said that he had not yet read the ruling party's election programme and that he would do that.
Milanovic said he believed the HDZ's programme incorporated good things as well, but added that the eight years during which the HDZ had had a chance to do good things were gone.
"They have shown who they are and how they manage the country," the SDP leader said.
When asked for a comment on opinion polls that gave the SDP a 17 per cent edge over the HDZ, Milanovic said he was not commenting on opinion polls.
"Elections are ahead of us and we need to win them," Milanovic said, adding that regardless of the latest developments, the HDZ was a strong political party and that the SDP should do its best to win the election.
Earlier in the day, the leader of the Croatian Party of Rights (HSP), Daniel Srb, described the HDZ programme as "wishful thinking".
Labour Party leader Dragutin Lesar criticised the HDZ platform as the continuation of social injustice.
The HDZ is afraid of levying taxes on the rich to the detriment of the poor, Lesar said. As for the economy, the programme will maintain the stagnation, he added.