ANKARA, (Reuters) – Turkey’s Prime Minister Tayyip Erdogan was involved in anti-secular activities, a top court said on Friday, explaining a decision to fine his AK Party that could reignite political tensions in the EU applicant country.

The constitutional court’s legal reasoning marks the first time a sitting prime minister in predominantly Muslim Turkey has been blamed by the court for undermining the country’s secular principles.

The ruling could put pressure on Erdogan to sack some members of his cabinet in an expected reshuffle.

The court, the highest judicial body in Turkey, decided in a close vote in July to fine the Islamist-rooted AK Party for Islamist activities, but dismissed a prosecutor’s case to have it closed down and Erdogan and other leading members barred from politics for five years.

“It was found that the head of the party Recep Tayyip Erdogan, member of the party and former parliament speaker Bulent Arinc, Education Minister Huseyin Celik…were involved in determined and intense activities which were against article 68 of the constitution,” it said.

In a 370-page legal explanation, the court singled out Erdogan and other senior members of the AK Party for attempts to lift a ban on the Muslim headscarf at university and efforts to lower the age at which students can attend Koran classes.

It also mentioned statements made by Erdogan in the past, including one in which he said “religion is the cement of Turkish society” and an interview to a Malaysian newspaper in which he described Turkey as a “modern Islamic state”. “Erdogan made it clear that his opinions on freedom of belief were aimed at creating an unlimited freedom for political Islam. This point of view was reflected in Erdogan’s and other prominent party members’ words and activities. There was an attempt to transform and restructure the state within the framework of the rules of a certain religion,” it said.

The court, however, said it voted againt banning the AK Party because it had not incited violence and because of its EU reforms, including giving more rights to minorities and to women.

Turkish markets are largely focused on the global economic crisis and shrugged off the court’s legal reasoning.

Analysts said the court’s ruling was a further warning to Erdogan, whose party is locked in a power struggle with the powerful secularist establishment, including judges and the military.

Secularists say the party is seeking to bring back religion to public life. The AK Party, which has its roots in political Islam, denies the charges and points to its liberal record since it first came to power in 2002.

“This shows the AK Party escaped closure very narrowly. The court is telling the party it must regulate itself and stay away from provocative policies such as the headscarf,” said Yusuf Kanli, a veteran Turkish columnist.

“It is also telling the party that the court might be compelled to ban it if it continues with its present trend,” he said.

Erdogan said on Thursday he might seek to trim the powers of the court after a ruling in June overturned an amendment to lift the restriction on wearing headscarves at university.

The AK Party, which includes former Islamists, conservatives and pro-business liberals, won a sweeping re-election last year.