Turkey's parliament has approved two constitutional amendments easing the ban on women wearing Islamic headscarves in universities.
The headscarf issue provokes strong reactions on both sides
The issue is deeply divisive in Turkey, where the state is strictly secular, and protests are expected.
The government said the ban meant many girls were being denied an education.
But the secular establishment, including generals and academics, see this as a first step to allowing Islam to figure more largely in public life.
Parliament voted 403-107 in favour of a first amendment, which will insert a paragraph into the constitution stating that everyone has the right to equal treatment from state institutions, Parliament Speaker Koksal Toptan was quoted by AP as saying.
MPs then backed by 403-108 votes a second amendment stating "no-one can be deprived of [his or her] right to higher education", AP said.
Opposition parties said in advance of the vote that they would challenge the changes in the constitutional court if they were passed.
A strict headscarf ban had been in force in Turkish universities since 1997. The ban came after the staunchly secularist military had exerted pressure to oust a government it saw as too Islamist.
The changes state that only traditional scarves will be permitted in universities, tied loosely under the chin. Headscarves that cover the neck are still banned, as is the chador and the all-enveloping burka.
Ural Akbulut, rector of the Middle East Technical University, in Ankara, says the changes represent the imposition of religious beliefs into the constitution.
"We say it will damage secularity," he told the BBC. "Once you do that - we believe you damage democracy."
The BBC's Sarah Rainsford says those who wear the headscarf dismiss that as paranoia.
They say the scarf is simply an expression of their personal religious belief.
As Turkey's population is predominantly Muslim, two-thirds of all Turkish women cover their heads, meaning thousands have been missing out on the opportunity to attend college. Many Turks argue that is unfair and there has been widespread public support for the move.
But tens of thousands of people who were against lifting the ban are expected to join protest rallies in the capital on Saturday.