BEIJING, CHINA: A Chinese lawyer has demanded a public hearing to reconsider a government demand that all new personal computers carry Internet filtering software, adding to uproar over a plan critics say is ineffective and intrusive.

Li Fangping, a Beijing human rights advocate who often embraces controversial causes, has asked the Ministry of Industry and Information Technology to allow hearings on the "lawfulness and reasonableness" of the demand, which takes effect from July 1 and was publicized only this week.

"This administrative action lacks a legal basis," Li wrote in a submission to the ministry that was sent to reporters by email on Thursday. "Designating that the same software must be installed in all computers affects citizens' rights to choose."

Li's demand, and denunciations of the plan from Chinese rights groups, have expanded a public battle over the "Green Dam" filtering software, despite a state media effort to promote the software as a welcome way to prevent children being exposed to pornography.

Many citizens worry such software and other measures are being imposed to deter discussion of sensitive political topics, especially in this year of controversial anniversaries, Li told Reuters.

"Above all, we're concerned about freedom of speech and the right to know," he said. "We know that citizens have been prosecuted because of their private emails, and we're worried about more such cases."

Chinese human rights and gay advocacy groups have demanded the software plan be immediately quashed.

A statement from five groups sent by email said the software threatened to cripple access to many of the gay community websites that have flourished in recent years.

The software works by judging whether website pages may show large amounts of exposed flesh.

Wan Yanhai, a leader of the Beijing-based Aizhixing organization, which works on AIDS and gay rights, said he was preparing a mass petition to mobilize opposition to the software.

"We need to demand not just the lifting of this software decree, but also an end to restrictions on gay publications," Wan told Reuters. "This is about opposing censorship."

Chinese state media have promoted the compulsory installation plan as an effective way to staunch the flow of pornography, which is banned in China but widely available.

"If you have children or are expecting a child you could understand the concerns of the parents over unhealthy online content," Chinese foreign ministry spokesman Qin Gang told reporters on Tuesday.

State television news said the software can be shut off and erased if users choose, and does not collect personal information.

China is one of the world's fastest-growing PC markets, and has hundreds of millions of Internet users. Research firm Gartner forecasts total PC shipments will climb by about 3 percent this year to more than 42 million units.

Li, the rights lawyer, said the ruling Communist Party is especially wary of dissent and controversy this year, the 20th anniversary of the 1989 pro-democracy protests ended by a bloody crackdown.

"How the government responds in the end will depend on the response from Chinese Internet users," he said. "If it's strong, they'll back down, and may let the plan quietly die."