Turkey’s secular establishment won an important battle on Thursday against the socially conservative government after the country’s top court struck down a move to allow girls to wear the Muslim headscarf at university.

The verdict of the constitutional court will prolong a paralysing political crisis that has gripped Turkey in recent weeks. It increases the likelihood that the ruling Justice and Development party (AKP), which has its roots in political Islam, will be shut down in a separate but closely linked case that accuses it of trying to undermine Turkey’s secular state.