The Peoples’ Democratic Party (HDP) said it was the victim of a “grave media embargo” even though it had received the votes of six million citizens in a nation of nearly 80 million.
The country’s second-largest opposition party, the pro-Kurdish HDP is calling for a ‘no’ vote on April 16.
Proposed changes to the constitution would create an executive presidency and axe the role of prime minister.
The party said data showed the Turkish state broadcaster TRT “brazenly violates” its own rules as well as the law of Turkey’s audiovisual authority, RTUK.
The HDP said it was given zero airtime on the TRT news channel between March 1 and 22.
No representative of the HDP was invited to a single television show across 17 national channels, it added.
Looking in detail at live broadcast and debate shows on TRT, the party said the presidency was given 1,390 minutes while the ruling Justice and Development Party (AKP), co-founded by Erdogan, was given 2,723 minutes.
Erdogan and Prime Minister Binali Yildirim have been speaking at rallies across Turkey on a daily basis, and these events are always televised.
Kemal Kilicdaroglu, the leader of the main opposition party, the CHP, has been travelling as well, speaking in rallies in support of a ‘no’ vote which are also broadcast live.
Last month a decree issued stripped the Supreme Election Board of its power to fine private channels if they did not give equal airtime to the different political parties and various views.
The HDP’s co-leaders Selahattin Demirtas and Figen Yuksekdag are currently in prison as well as 11 other HDP MPs accused of links to Kurdish separatists waging an insurgency against the Turkish state since 1984.
“It is true that the media in Turkey has never been completely independent from political power,” the party said.
“However, during no period of the history of the republic has the government had so much sway over the media.”