Britain accused China of using a national security law as a pretext to silence opposition after the Hong Kong media tycoon Jimmy Lai became the highest-profile person arrested under the new rule.

“This is further evidence that the national security law is being used as a pretext to silence opposition. The Hong Kong authorities must uphold the rights and freedoms of its people,”Prime Minister Boris Johnson’s spokesman said.

“We are deeply concerned by the arrest of Jimmy Lai and six other individuals in Hong Kong. Freedom of the press is explicitly guaranteed in the Sino-British Joint Declaration, and basic law, and is supposed to be protected under Article Four of the National Security Law.”

Mainland-born Lai has been one of the most prominent democracy activists in the Chinese-ruled city and an ardent critic of Beijing.

China supports media tycoon’s arrest

China supports the arrest of Lai by Hong Kong police, state media said on Monday, stressing the need to “severely punish” those who collude with foreign forces to endanger national security.

Lai, 71, is now the highest-profile person arrested under the new national security law in Hong Kong. A spokesman for China’s Hong Kong and Macau Affairs Office told the Xinhua agency that Lai was a representative of people who were “anti-China, anti-Hong Kong” and who were a danger that must be removed before there could be peace in Hong Kong. “He arrogantly called on people to fight for the United States, participated in the planning, organisation and instigation of a series of illegal protests,” Xinhua quoted the spokesman as saying.

He said that Lai also funded pro-independence forces and used his media to spread rumours and instigate violence. The spokesman said Lai and the others arrested on Monday should be severely punished, to show that “justice may be late but never absent”.

EU urges respect for human rights and press freedom in Hong Kong

The European Union urged respect for human rights and freedom of expression in Hong Kong on Monday, after Lai’s arrest. “The recent arrests of Jimmy Lai, members of his family and other individuals, and the raid on the offices of newspaper Apple Daily, under allegations of collusion with foreign forces,further stoke fears that the National Security Law is being used to stifle freedom of expression and of the media in Hong Kong,”European Commission foreign affairs spokesman Peter Stano said in a statement.

“The European Union recalls that the respect for human rights and fundamental freedoms is a central element of the Basic Law and the ‘one country, two systems’ principle.”