Georgian activists and politicians opposed to a government bill that critics say will stifle dissent have faced weeks of violence and threats, rights groups said Thursday.

A draft of the "foreign influence" law was introduced by the ruling Georgian Dream last month, sparking massive anti-government protests and a furious backlash from opposition groups.

If it passes, any independent organisation receiving more than 20 percent of funding from abroad would be labelled an "organisation pursuing the interests of a foreign power".

Citizens opposed to the legislation now face threats while politicians are being subjected to "physical assaults and organised reprisals", anti-corruption group Transparency International said.

Human Rights Watch said some of those taking part in rallies against the bill had been pepper sprayed or "viciously beaten by police" including a 17-year-old school student.

"The foreign influence bill tramples on fundamental rights and Georgian authorities should drop it," the organisation's Europe and Central Asia director Hugh Williamson was quoted as saying.

Critics say the bill, a similar version of which was scrapped last year following protests, mimics repressive legislation used in Russia and would upend Georgia's path to joining the European Union.

It has passed two readings in the Georgian parliament but to become law must pass a third, currently scheduled for the week of May 13.

At least four activists and politicians opposed to the government have been attacked in the past week, including Dimitri Chikovani, the public relations head of Georgia's main opposition United National Movement (UNM).

Flyers have also been affixed to the offices of politicians and media opposed to the bill, calling them "agents" and "enemies of the country", an AFP reporter in the capital Tbilisi saw.

Georgia's ambassador to France, Gocha Javakhishvili, resigned on Thursday in protest at the legislation, which he said frustrated Tbilisi's relations with foreign partners.