Istanbul - Seventeen directors and journalists from one of Turkey's most respected opposition newspapers go on trial on Monday after spending over eight months behind bars in a case which has raised new alarm over press freedoms under President Recep Tayyip Erdogan.The suspects were detained from October last year under the state of emergency implemented after the July 15, 2016 failed coup blamed on the US-based preacher Fethullah Gulen.The opposition fears the emergency has been used to go after anyone who dares defy Erdogan and if convicted, the defendants face varying terms of up to 43 years in jail.The trial is seen as a test for press freedoms under Erdogan in Turkey, which ranks 155th on the latest Reporters Without Borders (RSF) world press freedom index, below Belarus and the Democratic Republic of Congo.According to the P24 press freedom group, there are 166 journalists behind bars in Turkey, most of whom were arrested under the state of emergency.Erdogan, however, insisted in an interview earlier this month there were just "two real journalists" behind bars in Turkey.Blank space columnsCumhuriyet (Republic), which was set up in 1924 and is Turkey's oldest mainstream national title, has been a thorn in the side of Erdogan in recent years.It is one of the few genuine opposition voices in the press, which is dominated by strongly pro-government media and bigger mainstream dailies that are increasingly wary of challenging the authorities. A total of 17 staff of the newspaper - including writers, cartoonists and executives - will go on trial from 06:00 GMT at the imposing palace of justice in Istanbul.Those appearing in court include some of the best known names in Turkish journalism including the columnist Kadri Gursel, the paper's editor-in-chief Murat Sabuncu and the respected cartoonist Musa Kart.Also being tried in the case is the investigative journalist Ahmet Sik who in 2011 wrote an explosive book "The Imam's Army" exposing the grip Gulen's movement had on the Turkish state.The book was initially banned and caused a sensation when published on the internet as "000Kitap" ("000Book").Eleven of the 17 suspects including Gursel, Sabuncu, Kart and Sik, are held in jail with the other six free under judicial supervision. Being tried in absentia in the case is the paper's former editor-in-chief Can Dundar, who was last year handed a five-year-and-10-month jail term over a front-page story accusing the government of sending weapons to Syria.He has now fled Turkey for Germany.Those held will on the first day of the trial have been imprisoned for 267 days, with the exception of Sik, who has been held for 206 days.Since their arrests, Cumhuriyet has continued publishing the columns of the jailed journalists but with a blank white space instead of text.'Turkish journalism on trial'Supporters have labelled the charges against the newspaper staff as absurd and simply an attempt to muzzle the newspaper.They are charged with supporting in the newspaper's writings no less than three groups considered by Turkey as terror outfits -- the Kurdistan Workers Party (PKK), the ultra-left Revolutionary People's Liberation Party-Front (DHKP-C) and Gulen's movement, which Ankara calls the Fethullah Terror Organisation (FETO).But supporters insist that the paper has always been bitterly critical of the three groups, including Gulen's organisation. Gulen denies any link to the failed coup.The indictment accuses Cumhuriyet of beginning a "perception operation" with the aim of starting an "asymmetric war" against Erdogan."It's journalism in Turkey, not just Cumhuriyet, that is being put on trial," said RSF secretary general Christophe Deloire. "Journalists are yet again being treated as terrorists just for doing their job," he added.The UN Working Group on Arbitrary Detention, in an opinion released last month, said it found that the detention of the staff was arbitrary and that they should be immediately released and given the right to compensation.It said that their imprisonment "resulted from the exercise of their rights and freedoms" and said it was concerned by the "vagueness" of the charges of aiding terror groups.