Under the Public Consultation Code, a fortnight is a minimum required for public discussions on laws.
Goran Beus Richembergh of the ruling coalition's Croatian People's Party said the extension would enable everyone who had not had the time to do so to contact the committee.
Committee chair Pedja Grbin said everyone who had wanted to could have participated in the procedure for amending the Constitution so far. He said the committee had received 61 pages of remarks to the amendments and was hopeful that all would be included in a document the committee would send to parliament.
Dragan Zelic of the GONG NGO said a longer public discussion should have been called from the start. "All this has been an opportunity to learn how to treat constitutional changes. I hope our remarks will be seriously considered."
Dragutin Lesar of the opposition Croatian Labour Party suggested that all the records from the meetings of the group working on the constitutional amendments should be uploaded on parliament's website to eliminate suspicion of secret discussions.
Today's session was not attended by the strongest opposition party, the Croatian Democratic Union, whose MPs had walked out of the committee's meeting two weeks ago, dissatisfied with how Grbin led the committee.
Some committee members said unofficially that the Constitution would be amended by the New Year.