By MARC CHAMPION
ISTANBUL—Political tensions in Turkey escalated this week after one senior Turkish prosecutor arrested another, stoking a power struggle between the religious conservative government and secular establishment in the Middle East’s sole democracy.
The chief public prosecutor of Erzincan in northeastern Turkey was arrested Wednesday. According to state news agency Anadolu Ajansi, he was charged with misconduct, intimidation and being a member of an alleged terrorist conspiracy to topple the government.
The arrest was ordered by a special prosecutor pursuing a case against the alleged conspiracy—an effort that critics say has widened into a national crackdown on opponents of Turkey’s ruling Justice and Development party, or AKP. The arrested prosecutor, Ilhan Cilhaner, had previously opened an investigation into religious sects.
Mr. Cilhaner’s arrest inflamed the long-running battle between the AKP and Turkey’s judiciary, which is charged with enforcing the country’s strongly secular constitution. Many critics of the AKP see the country’s basic law as flawed but also the last defense against a government with Islamist roots they believe threatens modern Turkey’s secular foundations.
The country’s Supreme Board of Judges and Prosecutors, backed by Turkey’s top courts, protested Mr. Cilhaner’s arrest, stripping power from the special prosecutor and three other prosecutors who were involved.
In response, President Abdullah Gül called for rapid reform of the judiciary. Deputy Prime Minister Bülent Arınç, in comments Thursday, called the prosecutors’ demotion a “judicial coup.” He said the government might call a referendum on whether to rewrite the constitution.
Any attempt to do so could prove explosive. The EU and many Turks back changing the constitution, which was drafted in the early 1980s, in the wake of a military coup. The basic law includes clauses that have been widely used to repress ethnic and religious minorities in Turkey, as well as free speech. But critics of the AKP fear the document would be rewritten to reshape the nation in line with the party’s religious beliefs.
“The rule of law itself is under threat,” Deniz Baykal, leader of the main opposition Republican People’s Party, told reporters Thursday. “It’s the first time in our history that a court storms another court.”
Turkey’s chief prosecutor said this week he would examine whether the government was applying improper pressure on the judiciary. If the country’s courts agree that the party is in conflict with the constitution and threatens the state’s foundations, they could rule to shut it down, though such an outcome for now appears unlikely.
Analysts said investors didn’t appear to react to Mr. Cilhaner’s arrest, believing the two sides would continue to avoid escalating the conflict. The top 100 companies on the Istanbul stock exchange closed up 1.66% Friday, after falling with global markets during the week. Standard & Poor’s went ahead with a widely expected upgrade of Turkey’s sovereign credit rating to BB on Friday, citing a strong financial sector and solid fiscal polices.
Tensions between the judiciary and AKP run deep. Turkey’s courts banned the AKP’s predecessor Islamic parties and sought to ban the AKP in 2007. Turkish courts blocked the government’s attempt to lift restrictions on the wearing of head scarves in universities.
More broadly, Turkey’s religious and secularist elites have been engaged in a virtual civil war since 2007, when the AKP sought the presidency, traditional guardian of Turkey’s secular laws, for Mr. Gül. His candidacy was at first blocked in Parliament; the army issued a thinly veiled online threat to intervene against his appointment.
The government responded with snap elections and won convincingly. Since then, the government appears to have taken the offensive. In 2007, prosecutors launched an investigation into the alleged conspiracy known as Ergenekon. The effort was initially welcomed by the European Union and by Turks weary of military coups and abuses of power by unelected officials.
Alleged Ergenekon participants are accused of planning coups, stashing arms and carrying out assassinations. But the case has since ballooned to include hundreds of defendants, from generals to secularist journalists and academics.
This week’s arrest of a sitting prosecutor, who special prosecutors alleged is an Ergenekon member, was a first. Mr. Cihaner’s lawyer say he was targeted for his investigation into sects’ activities. The government has denied it ordered the arrest.