As a culmination of a series of clashes between the party that has Islamist roots, and the secular elite, Turkey’s Constitutional Court is meeting in order to consider whether the governing AK Party should be banned for alleged anti-secular activities.
Last year, the AKP won a huge poll victory, and now denies it wants to create an Islamist state by stealth, and calls the case an attack on democracy.
In Istanbul, 17 people were killed in a bomb attack, hours before the court opened, even though it was not clear if the attacks were timed to coincide with the controversial court case, that represents a clash between powerful forces.
Five children were among those killed and more than 150 people were wounded in the twin bombings, six of whom remained in hospital with serious injuries, said the governor of Istanbul.
The bombings only strengthened Turkey’s determination in its fight against terrorism, said the country’s prime minister, Recep Tayyip Erdogan.
He insisted his thoughts were with those affected by the bombings. In order to travel to Istanbul and visit the site of the attacks, he cancelled a Monday morning cabinet meeting.
When he was at the scene, Mr Erdogan downplayed the courtroom drama unfolding in Ankara, Turkey’s capital.
“Our problem is not whether or not AK Party will be closed”, Reuters news agency reported him as saying.
“Our problem at the moment is to keep our unity so our country will go in a different direction.”
In 1923, the modern Turkish republic was founded as a secular and unitary state. For allegedly posing a threat to those principles, more than 20 parties, mostly pro-Islamist or pro-Kurdish, have been shut down by the courts since the 1960s.
The BBC’s Pam O’Toole says that this is the first time that a closure case has been brought against a governing party with a huge parliamentary majority.
She adds that, with the AKP fighting for its political survival and the secularists viewing the case as their last opportunity to block what they allege are attempts to turn Turkey into an Islamic state, the stakes are high.
Though the party argues that it is facing a “judicial coup”, more than 70 AKP members, including president Abdullah Gul and Recep Tayyip Erdogan, could be banned from political activities for five years.
Until the 11 judge-panel reaches one of three verdicts, to shut down the party and impose political bans on its members, to cut treasury aid to it, or to throw out the case ; the Constitutional Court has said that it will convene on a daily basis.
The political fault lines between AKP supporters and secularists will be deepen if the party is closed down or large numbers of its senior members are banned from politics, says BBC’s correspondent. She added that it could lead to a period of political instability, or even another general election, with the AKP’s deputies regrouping under a different name.
An adviser to the court recommended, last week, that it should not shut down the AKP, arguing the constitution had not been challenged by its decision, in June, to lift a ban on Islamic headscarves in universities.
And in Turkey’s stock market, uncertainty has already been caused by the case.
And as the European Union has expressed concern, there is also speculation that Ankara’s long-running bid to join the organisation could be harmed by the ban.
Although major reforms aimed at EU membership have been pushed through by the AKP during its first term in office, critics say that in its second term, the party has focused more on policies aimed at its conservative supporters.