HONG KONG (REUTERS) - The trial of the first person charged under Hong Kong's national security law wrapped up on Tuesday (July 20), with the prosecution seeking to designate a slogan popular during 2019 protests as subversive in a crucial test of the city's rule of law.

Former waiter Tong Ying-kit, 24, has pleaded not guilty to charges of terrorism, inciting secession and dangerous driving causing grievous bodily harm on July 1 last year, shortly after the law was enacted.

As the first national security case conducted in open court, Tong's case could set precedents on the handling of security law cases for the more than 120 other people charged under it, including prominent democrats and activists.

The verdict will be delivered on July 27 by a panel of three judges; Esther Toh, Anthea Pang and Wilson Chan - who were picked by Hong Kong's pro-Beijing leader to hear national security cases.

Tong faces up to life in prison, as set out in the national security law. Someone convicted of a "grave" national security offence could be jailed for at least 10 years, the law says. Tong was denied bail and a jury, factors that stoked concern among some Western governments and rights groups as a significant departure from century-old common law traditions.

The court had cited the safety of jurors and their family members in denying trial by jury. Defence lawyers argued that the right to a jury was a "hallowed principle" of the common law system.

On July 1 last year, a day after the law came into effect, Tong rode a motorcycle with the protest slogan "Liberate Hong Kong, Revolution of our Times" fluttering on a flag from the back as he drove into a group of riot police, injuring three of them.

He was arrested and charged with "incitement to secession"as well as terrorism and dangerous driving. Tong has pleaded not guilty to all charges.

The interpretation of the protest slogan, which was spray-painted on walls and chanted regularly during anti-government demonstrations that roiled the Chinese-ruled city in 2019, has been at the heart of the trial.

In his closing submission, government prosecutor Anthony Chau argued that Tong had displayed the flag to incite others to commit secession, including protesters gathered nearby, some of whom clapped as Tong rode past. He also said that Tong had used his motorcycle as a "lethal weapon" and the slogan on his flag showed he was "pursuing a political agenda".

The government has long held that the slogan suggests a call for independence, which would violate the security law, though no legal ruling has been made on that interpretation. Tong's defence lawyer, Clive Grossman, argued on Tuesday it was a phrase with "multiple interpretations", including the desire for freedom and democracy. Much of the trial involved debate between professors drawing on a range of topics including ancient Chinese history, the US civil rights movement and Malcolm X, to ascertain whether the"Liberate Hong Kong" slogan is subversive.

Two expert witnesses called by the defence to analyse the slogan's meaning, drawing upon sources including an examination of over two million online posts, found "no substantial link" between the slogan and Hong Kong independence, Grossman said.

Prosecutor Chau, however, challenged, that, saying this"empirical data analysis is irrelevant, and not reliable" and could not assist the court in understanding the meaning of the slogan.

Tong's case has been closely watched in the city of 7.5 million. Critics say it shows Hong Kong's rule of law is under strain with the upending of common law traditions that had been a bedrock of the city's success since Britain handed it back to China in 1997 under a "one country, two systems" formula aimed at preserving its freedoms and role as a financial hub.

Those traditions include the presumption of bail, the presumption of innocence and the right to a jury, according to submissions by defence lawyers reviewed by Reuters. The government has said that all prosecutions have been handled independently and according to law and that legal enforcement action has nothing to do with the political stance, background or profession of those arrested.

The defence argued that Tong hadn't undertaken a terrorist act with his motorcycle. A shield allegedly thrown by a policeman as he rode by, Grossman said, could have been a reason for the "accident or a collision" with the officers.