There may have been three police vehicles trailing us, but Aminatou Haidar was upbeat. As she posed for photographs outside the disused prison where she had once been detained and, she says, tortured, an armour-plated police van drove slowly past.

"I am always followed by the police," said Haidar, with a shrug.

"But at least, I have some level of protection, because they are afraid of doing something obvious against a person who is very well-known internationally."

That was a year ago, in the desert city of Laayoune, in the Moroccan-controlled territory of Western Sahara. Haidar is now even better known, having since won two major American human rights awards. Yet that protection proved to be short-lived.

Last week, Haidar was expelled from Western Sahara by the Moroccan authorities, and her passport confiscated. She was put on a plane to Lanzarote, where she has refused to leave the airport and has started a hunger strike, demanding to be allowed return to her family in Laayoune.

Her expulsion marks a new turn in the Western Saharan conflict, a conflict which, largely ignored by the international media, has been ongoing for almost 35 years, and one in which Ireland has played a positive role on a number of occasions. (Since a ceasefire in 1991, the conflict has been political, not military.)

Known as "Africa's last colony", Western Sahara was, till 1975, a colony of Spain. Spain withdrew, and the UN's International Court of Justice ruled that Western Sahara had the right to self-determination. In response, Morocco invaded.

Many of the indigenous people, the Sahrawis, fled east, across the border, into Algeria, and built refugee camps. They're still there. Their liberation movement, the Polisario Front, established a government in exile and fought back against the Moroccans. Within Western Sahara, expressions of support for self-determination, or of Sahrawi culture or identity, were banned.

In 1991, Morocco agreed to a referendum on the territory's status, and a ceasefire was agreed. The United Nations sent in peacekeepers; thanks, in part, to rigorous monitoring by the blue helmets, Irish soldiers among them, the ceasefire has held. But the referendum has never happened, due largely to Moroccan delaying strategies.

Ireland was instrumental in blocking one such attempt, during our period on the UN security council, from 2001 to 2002, when Morocco's traditional allies, France and the US, had proposed to allow people with just one year's residence in Western Sahara to vote in the putative referendum. (Moroccan settlers would thus have qualified to vote, skewing the referendum in Morocco's favour.)

The referendum process has since stalled, with, at best, occasional bouts of talks about talks. Barack Obama's elections raised hopes of a renewed US engagement with the issue, but secretary of state Hillary Clinton, visiting Morocco recently, emphasised that US policy remained as it had under the Bush and Clinton administrations: the US backs a Moroccan "compromise" that offers Western Sahara "autonomy" under Moroccan control.

Amidst this political stasis, Western Saharan activists have mobilised under the banner of human rights, attracting sometimes-violent attention from the security forces, but also support internationally. Last year, myself and Sunday Tribune photographer Mark Condren travelled to Western Sahara with the charity Front Line to meet these activists, foremost among them Aminatou Haidar.

Haidar told us of the four years in the late 1980s that she spent mostly blindfold, in a Moroccan "black site" prison, sharing a cell three metres square with nine other women, for helping to plan a pro-independence rally. She spent a further spell in prison in 2005, during which she went on hunger strike.

Many others told stories of imprisonment, abuse and torture by Moroccan security services. Every time we left our hotel, we were visibly followed. Travelling to another town, we were stopped at a multitude of checkpoints. Our hotel rooms were broken into.

Yet it seemed that there was official recognition that activists like Haidar were too well known to be overtly harassed. Earlier this month, however, that changed. Morocco's King Mohammed VI signalled a new, tougher line in a major speech.

"It is time to stop outlaws taking advantage of [Morocco's] civic freedoms to agitate from within," he said. "You are either a patriot or a traitor."

Aminatou Haidar clearly signalled her attitude when, on returning from the US last week, she refused to write her nationality as "Moroccan" on the landing card at the airport. Deciding that she had thereby waived her citizenship, the Moroccan authorities duly threw her out.

With a growing international outcry, and Haidar's self-imposed threat to her health, Spain has intervened: this weekend, there were signs that Spain might broker a compromise to enable her return to Laayoune.

The controversy would be farcical were the wider issue not so serious. In refugee camps in the desert, 140,000 people rely chiefly on humanitarian aid to survive. In Western Sahara itself, indigenous culture and identity, and its champions, are repressed, often violently. The world is barely watching, and so the situation continues.

Ireland has championed Western Sahara's right to self-determination before. It is time to do so again.