Turkey’s top court said on Friday that Prime Minister Tayyip Erdogan and key members of his ruling AK Party had been involved in anti-secular activities, a move likely to renew political tensions in the EU candidate country.

The Constitutional Court, Turkey’s highest judicial body, was setting out the reasons for a July ruling in which it decided not to close the AK Party for Islamist activities but instead fined it for undermining Turkey’s secular principles.

“It needs to be accepted that the party became a focus of anti-secular activities due to its move to change some articles of the Turkish constitution,” the court said referring to an AK Party-driven attempt to lift a ban on the wearing of Muslim headscarves at universities.

In a setback to the Islamist-rooted AK Party, the constitutional court in June overturned an amendment to lift the restriction, saying it violated Turkey’s secular constitution.

The court’s unexpectedly harsh criticism against Erdogan, who remains Turkey’s most popular politician according to recent opinion polls, is likely to renew tensions in Turkey at a time when it is fighting to limit the impact of a global financial crisis.

Turkey’s top court also found Education Minister Huseyin Celik, among others, was involved in anti-secular activities.

The constitutional court imposed financial penalties on the party in July but dismissed the prosecutor’s case to have the AK Party closed down and to bar Erdogan and other leading members from party activity for five years.

The AK Party has been locked in a battle with Turkey’s powerful secularist establishment, including judges and army generals, since it first came to power in 2002. Secularists say the party is seeking to bring back religion to public life, contrary to the constitution.

The AK Party, which won a sweeping re-election last year, denies it has any Islamist agenda.