As the Olympic torch heads up Everest on the next phase of its troubled journey next week, it is almost certain to attract more protests as it gets closer to Tibet.

But peaceful demonstrations must go ahead: what's becoming clear is that the real opportunity to protest against the Chinese government's treatment of its people will be from outside the country. The authorities are gradually strangling dissent within China to ensure that the Games in August go off without any embarrassing protests. The crackdown on human rights activists in China has intensified in the last nine months. It has never been easy for people to speak out about issues like political freedom, the death penalty, HIV/AIDS, land grabs, or the environment - I know this from personal experience - but if anything, things are getting worse.

Back in 1989 in Beijing I helped organise the pro-democracy protests in Tiananmen Square. We held public discussions around sensitive political issues. After the Tiananmen massacre, I was arrested and held in prison for 18 months, followed by repeated harassment and detention. But I was still one of the lucky ones.

Many of the participants were killed - their relatives built the network called the "Tiananmen Mothers". Many are still in prison, among whom is Hu Shigen, a lecturer at Beijing Language Institute, who was sentenced to 20 years in prison in 1992 for commemoration of 4 June victims. I escaped in 1997 and now live in the UK, where I'm free to protest at China's human rights record; a right I exercised, peacefully, when the Olympic torch came to London.

But the situation for those I left behind is quite different. An Amnesty report earlier this month spelled it out: "Much of the current wave of repression is occurring not in spite of the Olympics, but actually because of the Olympics". Dissenters are targeted and silenced. Anyone making direct connections between human rights abuses and China's hosting of the Olympics is treated particularly harshly.

Ye Guozhu is serving a four-year sentence after he applied for permission to hold a demonstration about forced evictions in Beijing. He has reportedly been tortured with electro-shock batons in prison. Wang Ling, his associate, had also campaigned publicly after she lost her property as a result of Olympic construction. She was recently thrown into a "Re-education through Labour" camp for 15 months, where conditions are notoriously harsh. We got a clear hint as to what conditions will be like during the Games when the Ministry of Public Security held a press conference in November 2007 to lay down the law about public protests. Anyone wishing to hold assemblies, parades and demonstrations during the Olympics, they announced, would have to comply with the law - including an obligation to apply for permission in advance. As Ye Guozhu's case shows, such permission is almost never granted. And the consequences for those who try to protest peacefully can be dire.

In March this year, Yang Chunlin was sentenced to five years in prison for "inciting subversion" following his "We don't want the Olympics; we want human rights" campaign, which was meant to defend peasant rights from land seizures by developers and officials. It's reported that he was tortured in police detention: for seven days in August and September 2007, his arms and legs were stretched and chained to the four corners of an iron bed so that he couldn't move. He was forced to eat, drink and defecate in that position. On 3 April, human rights activist Hu Jia was sentenced to three and a half years in prison for "inciting subversion of state power" when he spoke up for imprisoned civil rights lawyers. Earlier this year more activists were detained or put under surveillance and there were broad police sweeps of petitioners, vagrants, beggars and other "undesirables" in Beijing, ahead of the National People's Congress. The Party likes its big events to go smoothly; no one is going to be allowed to get in the way. And there is no bigger event than the Beijing Olympics.

Recent events in Tibet highlighted the situation yet more clearly. The crackdown on the peaceful protests of 10 March and what followed - violence from the police and the army, mass arrests, "wanted lists" of protesters posted online - showed that the authorities' attitude to peaceful demonstrators hasn't moved on much in 19 years. But they have learned to keep the media away.

Amnesty releases the first of four online animated films today, highlighting the crackdown on peaceful protests in China and asking people here to join its "Human Rights For China" campaign. Campaigning techniques have moved on considerably from our 1989 protest camp. Sadly the attitude of the Chinese authorities to peaceful protest has barely moved an inch.