Turkey's parliament has passed a new legislation to shut down private preparatory schools, many of which are run by the movement of an influential United-States-based Muslim cleric that has been in a political rivalry with the ruling Justice and Development Party (AKP).

The move, which was passed late on Friday, will strike a blow to the movement of Fetullah Gulen, who Prime Minister Recep Tayyip Erdogan accuses of running a covert campaign to topple his government.

The schools are a major source of income and influence for the movement.

In the vote, Turkish members of parliament set a deadline of September 1, 2015 to close the schools, which millions of students attend to prepare for central high school and university entrance examinations.

Erdogan has said that abolishing the preparatory schools is part of a larger reform of an "unhealthy" educational system that places Turkey below the Organisation for Economic Cooperation and Development average in literacy, mathematics and science.

The law allows some of the preparatory schools to become private high schools, giving them free access to properties that belong to the Treasury. Furthermore, the Education Ministry is to recruit some of the preparatory school teachers to work in public schools.

Tense relations

The government blames Gulen, whose followers wield influence in the police and judiciary, for conducting corruption investigations to compromise Erdogan. The scandal broke with police raids on December 17, but ties between the AKP and Gulen movement, which used to be political allies, have been tense for several years.

The government's initial moves to shut down the preparatory schools late last year escalated those tensions ahead of March 30 municipal elections, which are seen as a critical test of support for Erdogan after 11 years in power.

Following the launch of the investigations, in an apparent move to get over Gulen’s judiciary and police forces, the AKP initiated a country-wide comprehensive overhaul in the Turkish Police Force and pushed a new law in the parliament that increases the influence of the government over the judiciary.

Followers of Gulen, who preaches respect for science, democracy and dialogue with other faiths, have forged a powerful socio-religious community network active. Gulen, who says he has no plans to form a political party, denies any involvement in the corruption investigations in question.