The draft law aims to tackle separatism, subversion, terrorism and collusion with foreign forces, though it is unclear what activities would constitute such crimes and what the punishment would be.
"I will probably be the prime target of the new law. But what makes me fear is not my potential imprisonment, but the gloomy fact that the new law will be a threat over the city's future," he told Reuters.
Some details of the law were released after China's top legislative body, the National People's Congress, met last week. It is set to meet again from Sunday (June 28), according to a report by the official Xinhua news agency.
The Global Times, a tabloid published by the People's Daily, has cited "observers" as saying the parliamentary body would likely enact the Hong Kong security law by July 1, a day pro-democracy groups rally every year to mark the anniversary of the city's handover to the mainland.
One of the most globally recognised faces in Hong Kong's pro-democracy movement, Wong, 23, began his activism during secondary school when he led a hunger strike against a national education system and later became one of the protest leaders for the 2014 pro-democracy Umbrella Movement. Wong has been imprisoned several times over his participation in the 2014 protests. In 2019, he was sentenced to two months in May and was released during the height of last year's protests in June.
He announced plans last Friday (June 19) to run for a seat in the city's legislature despite being barred from running in previous polls.
"We don't want the last beacon of liberty on China's soil (to) fall into the tyranny and the hardline of President Xi Jinping," he said.
The draft law has alarmed foreign governments and Hong Kong democracy activists, who are concerned that Beijing is eroding the high degree of autonomy granted to the territory when it was handed over to China in 1997 from British rule.