By Sarah Rainsford
BBC News, Istanbul, Turkey
It is a snapshot of modern Turkey: two girls walking arm-in-arm along Istiklal Street in Istanbul, one dressed in a long skirt and headscarf, the other in a tight-fitting top, hair flowing freely.
A total of 63% of Turkish women now cover their heads in public
But enter any university here - state or private - and there will not be a headscarf in sight.
No female MP covers her head in parliament and women who do wear the headscarf were deliberately left off the guest list for this year's Republic Day reception at the presidential palace in Ankara.
Mainly Muslim Turkey was founded as a strictly secular republic. The right of women to wear the Islamic headscarf is at the heart of a fierce debate.
That debate has intensified since the current government came to power, formed from a party - the AKP - with roots in political Islam.
"If the prime minister has changed his views, why does his wife still wear the symbol of political Islam on her head?" asks newspaper columnist Leyla Pavsanoglu, her own dark blonde bob carefully coiffured.
Like many staunch defenders of secularism, she is convinced the government has an Islamic agenda.
"They say they want to turn to the West, but what kind of Western style is that? It is very obvious they are trying to hide their real intentions."
There is a widespread perception here that the number of women covering their heads in public is increasing. The most common theory is that covered women feel more comfortable now a pro-religious party is in power.
According to information leaked from an opinion poll due out later this month, 63% of Turkish women now cover their heads outside the home.
Turkey's secular establishment warns of a surge in fundamentalism
However the majority of those wear a traditional, non-Islamic head covering. A tiny percentage choose the full cover of the chador and just 11% of respondents wear the turban - or religious headscarf - which is neatly pinned at the sides, leaving the face exposed.
Perhaps more interesting is that all the figures have fallen since the last survey on the same issue six years ago.
But perceptions are as important here as facts.
Turkey's secular establishment - which includes the powerful military, the president and the judiciary - has begun uttering stark warnings about an apparent surge in fundamentalism.
"Are there not people at the very top layer of government who seek to redefine secularism at every opportunity?" army chief of staff Gen Yasar Buyukanit demanded in his first public speech after taking office.
If so, he said, "there is a threat from reactionary forces here and every measure must be taken against it".
That kind of rhetoric has been mounting as presidential elections draw closer.
Ever since Kemal Ataturk founded the republic, its president has been drawn from secular circles. Now the AKP has a majority in parliament and, come next spring, the party could well take the presidency.
Thousands of Turks marched in defence of secularism
For the first time, the first lady of the republic would wear an Islamic headscarf.
It was partly opposition to the prospect of an AKP president that brought huge crowds onto the streets earlier this year.
The mass demonstrations were in defence of secularism, after a gunman shot a senior judge in Ankara, claiming it was punishment for the judge's strict enforcement of restrictions on the Islamic headscarf.
"Turkey is secular and will stay secular," the crowds shouted then in response.
Many hurled abuse at ministers who attended the funeral of the judge, accusing the government of fuelling the attack by campaigning to relax the rules on the headscarf.
But women who wear the headscarf argue they are unfairly discriminated against in Turkey for their religious belief.
"I have been wearing my headscarf since I was 14. This is how I express myself. I do not aim to impose anything on others," explains Leyla Shahin, who was expelled from medical school for refusing to remove her headscarf.
"I do not think anyone has the right to tell me what to wear. The problem is not me, it's the other side that intentionally misunderstands what I am."
"The idea that the headscarf is a threat is ridiculous," another young covered woman protests, as she visits an Islamic clothing shop in Istanbul.
"I wear my scarf of my own free will. I just don't understand why people are against it."
'We are losing'
Conservative fashion shops say business has boomed in recent years. But shop owner Mustafa Karaduman argues Turkey's secularists have nothing to fear from that.
"People thought this government would solve the headscarf issue and the problems of religious schools. They thought the Islamic community would get its human rights," Mr Karaduman complains, speaking amidst racks filled with loose-fitting shirts and skirts and headscarves. He supports the very marginal pro-Islamic party the AKP split from.
"But nothing has happened. The government has modernised, secularised. We are losing."
The government itself insists it fully supports the principles of Ataturk's revolution. Prime Minister Recep Tayyip Erdogan told a conference this week that his party was "working for the secular state to succeed".
It is under close scrutiny from suspicious secularists every step of the way.