Vietnam's government has made it clear it will not tolerate criticism of one-party rule even as it asks the public for suggestions over revisions to the country's constitution.

A group of intellectuals and former officials used the government's invitation for input to issue a petition calling for multiparty democracy and other reforms, turning what was an attempt by the Communist Party to boost its legitimacy into a rare arena for dissent.

The head of the committee overseeing the constitutional reforms said people were "abusing" the invitation to "propagandize and lobby for the people to oppose the party."

One of the intellectuals who signed the petition says he won't shut up.

Le Hieu Dang said Thursday that "we need to have open discussions."