The HDZ's motion will be on the agenda of talks with other coalition partners next week.
Under the proposal, the margin in constituencies' size may be 2.78 percent while the existing legislation provides for a margin of up to five percent.
Kosor said that her party as well as the entire ruling coalition would work diligently on closing in June the negotiating area No. 23 "Judiciary and Fundamental Rights" in Croatia's European Union accession negotiations.
We remove obstacles each day, she told reporters, adding that she was sure more than she was ever before that Croatia would do that job on time.
Asked by reporters whether she would positively respond to the invitation from Vesna Pusic, chairwoman of the national committee overseeing Croatia's EU entry negotiations, to attend, along with President Ivo Josipovic, a meeting focusing on efforts to bring the EU entry talks to conclusion, Kosor said she was glad that Pusic had recognised the government's efforts in this regard.
"Certainly, we will talk," she said.
Asked whether there was a risk for Croatia to complete the technical part of the negotiations but to be hindered on the path to the EU due to political views of some EU members, Kosor said that earlier this week she had visited Brussels and attended the European People's Party summit meeting at which she received support from many EU leaders.
She said that European Commission President Jose Manuel Barroso would soon visit Croatia.