When Her Royal Highness Basmah Bint Saud first enters the Gladstone Library of the Oxford Union, where we are to meet before her speech, I’m surprised. The dissident Saudi Princess, human rights campaigner and women’s activist is small and bird-like, glamorous, wearing stiletto heels and a leopard-print scarf. She is being told about the college coats of arms that decorate the ceiling. None of the all-women colleges are up there, her guide says. “Why?” There’s a pause. “I’m not going to like this, am I?” she laughs.

Despite being 115th daughter of the former King Saud, and niece of the current King, Her Royal Highness grew up far from the Court of Al Saud. Her father was overthrown by his brother Prince Faisal in 1964, and the Princess’s mother“fled with her children to Lebanon. When civil war broke out in the country the family moved again to England, where the young Princess was educated. She later studied in Switzerland, before returning to Beirut to take a degree in Medicine, Psychology and English.

Since then, HRH has been a vocal advocate for reform in Saudi Arabia. Ruled by an absolute monarchy, the country takes Islamic law as the basis for its system of governance. Corporal punishment is still practised, with flogging regularly imposed as a sentence by the courts. Male guardianship is the norm, and tribal customs prizing namus (honour) underpin the treatment of women in society. In 2009, the World Economic Forum ranked Saudi Arabia 130th out of 134 countries for gender parity, though there have been limited reforms in recent years. In 2011 women were finally granted the right to vote.

As a young woman, HRH spent time in rural Saudi Arabia observing, and writing about, women’s rights on the ground. She is keen to point out however that women’s inequality is not specific to that country. “Everything hits women hardest, even here.” She points to gender inequality in France, Britain: “Women are women everywhere. We are second-class citizens, everywhere. It is a global issue.”

But is it not particularly bad in Saudi Arabia? “Look,” she tells me, pausing. “A Muslim man in Britain who keeps his woman veiled keeps her at home. Can British law bring her out? So what is the difference between her living here, and in Saudi Arabia? At least we know we have no laws, nothing to protect us. At least we know we’re not free on the street. But you don’t.”

What she offers is a radical solution. “At the end of the day, matters are not resolved by doing speeches. Everybody just shakes hands, and I go back home, you go back home, and nothing changes – there’s no implementation of anything we say.

“I think if the ball starts from the top of the mountain, by the time it rolls down to the bottom of the valley it will be so huge it will cover everything. Like an avalanche. It has to start here, at the top,” she looks around at the oak-panelled library of the Oxford Union. “It will roll down to our country. It has to be global. It has to be a global pressure.”

She is wary of focusing particularly on the problems of Saudi Arabia, wary of directly criticising the monarchy. Asked about the possibility of revolution, she says: “people think Saudi Arabia is immune from revolution. Everyone thought the whole Gulf was immune from revolution – but nobody is.” But she moves the topic onto a global scale, as with France and women’s rights, telling me how she had just come from Edinburgh, where she got into a conversation with a shopkeeper: “he said, ‘where are you from?’ and I said, you know, Saudi Arabia, Beirut, Jordan, etc. and he brought up revolution. He said, ‘you know, we’re looking for our freedom, too – our independence!’ And I looked at him, and thought I keep hearing of revolution everywhere. And now I hear it in Scotland!”

Her voice grows quiet. “It’s a global feeling. It’s a global status. Nobody’s happy.”

Initially her uncle, the Saudi King, encouraged her to write, she says. Out on the street, with the people. “I started shedding light on so many problems that he wasn’t aware of. I was like a tool, like a flashlight. The people around him weren’t transmitting that message.” But in recent years she has begun to be more heavily censored by the state as a result of becoming increasingly outspoken. “I became a nuisance to everybody, and then… And then I said I would come here, and relieve [them].” There is a pause. “I really don’t want to disturb the equilibrium in Saudi Arabia,” she says.

She is highly critical of conservative Imams, however. A scholar of Islam, she believes that the Quran “just hasn’t been interpreted by the right people.” Saudi Arabia’s legal system is based on Sharia law, which is interpreted by individual judges and the Council of Senior Religious Scholars, who all exercise sizeable discretionary power. HRH bin Saud argues that education is central to the people’s willing acceptance of what she feels is often essentially incorrect interpretation of the Qur’an. “The Qu’ran is written in very traditional and old language. To be able to translate it into a common language…” she pauses, and changes tack. “You have to write books, and educate children in schools.” The emergence in the past 20 years of an “intolerant” education system has taken Saudi Arabia to “a completely different corner of the world”; a world of intolerance that she says “doesn’t exist in Islam”.

She blames extremist factions for bias in the Saudi education system: “Everything has moved towards religious extremes.” She mentions September 11th. “Mr Bush said to crusaders, ‘battle’. He made that speech which set the tone, and everyone hung onto it. Otherwise, we would never have gone down that road.”

In the course of our interview, the Princess flows rapidly from radical to conservative; from respectful of the status quo, to contemptuous of the sluggish pace of reform. Sometimes it seems that she’s sticking to a script, a set of phrases and thoughts that have been pre-approved. It’s a tricky balancing act, between what I imagine are her real inclinations, and the relative conformism she has decided to adopt.

At the picture session before our interview, the Princess whips on a headscarf, “for the sake of the media”. This exemplifies her approach to activism. I can’t help but wish that this incredibly intelligent and powerful woman before me would just leap off the tightrope and take a stand.

She doesn’t say anything that will upset too many people, and when we come close, she deftly steers the conversation away from anything too heavy. In our final moments, I ask what keeps her awake at night. At this point my stomach rumbles loudly, and I apologise. She laughs: “What keeps me awake at night? Other people’s stomachs rumbling, when mine is full.”