With her bouquet of roses and fluffy white dress, Han Xincheng looked the epitome of the glamorous modern Chinese bride. But, although her parents had been pressing her to marry, the photographs were not what they might have expected: she is gazing adoringly at another woman, surrounded by onlookers.

The series of "wedding pictures" staged by lesbians and gay men in the heart of Beijing might not raise eyebrows any longer in most western countries, but they are evidence that attitudes are finally changing in a country where gay sex was illegal until 1997 and homosexuality classified as a mental illness until four years later.

There is still no legal protection against discrimination in China and few role models: no mainstream figures are openly gay. Yet now parts of China's gay population are calling for the right to wed - and meeting with some sympathy.

"Many reactions were quite positive and some people even came up to give us their blessing," said Han, though she acknowledges that overall the public reaction was negative.

One Chinese news report attracted 15,000 comments online - more than half disapproved. These days there are gay and lesbian bars in most big cities in China. There are unofficial magazines, NGOs that work with the community, even government funding for grassroots work, albeit mainly connected to tackling HIV. But, as in many countries, the gulf between attitudes in large cities and small villages can be stark. And the Chinese gay community faces different problems to its counterparts in the west: the censorship of gay books and films, the closure of bars and culture festivals, the variable tolerance of NGOs in general.

Police did not try to halt the recent event, but participants stressed they were friends who just decided to act and were not part of an organisation.

Li Yinghe, an academic at the prestigious Chinese Academy of Social Sciences, has repeatedly proposed legalising gay marriage, but thinks the Chinese political system must develop first.

"When there are ways to deliver these demands, this issue can be put on the agenda. Maybe it will take 10 years - maybe it needs decades," she said.

Yet the underlying ground may be fertile. Gay men and lesbians say there is less overt hostility than in the west and certainly less physical harassment. Li's research in cities suggests about 91% of people are happy to work with gay colleagues - a higher rate than in US surveys - and that 30% back gay marriage.

She argues that Chinese culture has historically been more tolerant than others: "We don't have religions which are absolutely against homosexuality, for example. But the pressure to marry is huge - far greater than in the west."

Han, 27, thinks her parents know she is a lesbian. "But my mum told me I must have experience of marriage, no matter how long it lasts. I don't think she hopes to change my sexuality, she just thinks my life will be more stable," said the media professional.

For Dana, the other "bride", Chinese culture's stress on marrying and continuing the family line is precisely why the right to wed matters.

"Family is such an important concept here; people aren't supportive of homosexuality because they basically believe same-sex couples can't form a family. If we have stable families, society will see we are safe, that we are mainstream," said the 24-year-old student, who asked that only her English nickname be used.

Others want to safeguard their legal rights in a relationship, while another participant, Xian, hopes the very boldness of the demand will raise the profile of a community whose biggest problem is ignorance, not hostility.

"If the public don't know about us, they won't include us in anti-discrimination law. For me the main goal of this event is raising our visibility and opening up a space to discuss these issues," she said.

Sun Dehua is the embodiment of increasing awareness and tolerance: a farmer who plotted to blow up his son's gay bar because he was so appalled by his homosexuality, but who now runs a hotline for the parents of gay children.

"I believed he had been led astray by bad people or we would have a daughter-in-law and the happiness we deserved. I felt my whole life depended on him and I didn't want to live any more. I was so angry I wanted to kill him and myself," he said.

But when his son fled the city with his boyfriend, both fearing for their lives, Sun began to think again. Now he has bought a house for the couple and hopes that one day they can wed. "These people want marriage and it's their right. We must learn to accept them," he said.