The UK remains “deeply concerned” about the crisis in Hong Kong and Number 10 has raised the issue with Beijing’s ambassador in London.

Hong Kong’s leader Carrie Lam insists national security legislation proposed by China’s legislature will not threaten the semi-autonomous territory’s civil rights.

But Downing Street said it has raised concerns with both Hong Kong and Beijing.

After police used tear gas and pepper spray on pro-democracy protesters over the weekend, the Prime Minister’s official spokesman said the scenes were “deeply concerning”.

“We have always said that it is essential that protests are conducted peacefully and the authorities avoid any actions that could inflame tensions,” the spokesman said.

He underlined the UK is “fully committed to upholding Hong Kong’s autonomy and respecting the one country, two systems model”.

China’s ambassador to the UK Liu Xiaoming warned Britain against interfering in the affairs of its former colony.

“Maintaining Hong Kong’s stability and prosperity serves the interests of both China and the UK,” he said.

“Interfering in Hong Kong’s affairs does not only damage China-UK relations but also harm UK’s own interests.”

Hong Kong needs this piece of legislation for the bigger benefit of the great majority of Hong Kong people

Ms Lam defended the change being considered by China’s ceremonial National People’s Congress amid concerns about its impact on civil liberties.

She said: “Hong Kong has proven that we uphold and preserve those values.

“Hong Kong needs this piece of legislation for the bigger benefit of the great majority of Hong Kong people.”

She repeated claims the law will only target “a minority”, citing concerns about terrorism and subversion.

Such a move by Beijing has long been under consideration and was hastened by last year’s street protests in the former British colony, which was returned to Chinese rule in 1997.