The constitutional reform referendum will possibly be held on April 16, Justice Minister Bekir Bozdağ said on Thursday.

"The date for the referendum is April 16 if the bill is approved [by President Recep Tayyip Erdoğan] today, tomorrow or the next day," Minister Bozdağ told state broadcaster TRT.

Parliament approved the constitutional amendments on Jan. 21, after deputies completed two rounds of voting on 18 articles. A total of 339 deputies voted in favor of the package, which will be put to vote in a national referendum.

The constitutional reform and the change to a presidential system has been on the political agenda since Erdoğan, a former prime minister and leader of the Justice and Development (AK Party) Party, was elected president in August 2014. This marked the first time a Turkish president had been directly chosen by a popular vote.

On Dec. 30, a constitutional committee of deputies from the ruling AK Party and the opposition Nationalist Movement Party (MHP) submitted a proposed bill to Parliament for ratification.

Two opposition parties, the main opposition Republican People's Party (CHP) and the Peoples' Democratic Party (HDP), remain opposed to the proposed changes.