Britain's government on Friday vowed to stand by the people of its former colony Hong Kong against a Chinese crackdown as it prepared to launch a new visa scheme potentially benefiting millions.
Holders of British National (Overseas) status -- a legacy of UK rule over Hong Kong up to 1997 -- will from Sunday be able to apply to live and work in the UK for up to five years, and eventually seek citizenship.
Before the change, BN(O) passport holders have had only limited rights to visit the UK for up to six months, and not to work or settle.
The UK says it is acting in response to a National Security Law imposed by China last year which has devastated Hong Kong's democracy movement and shredded freedoms meant to last 50 years under the 1997 handover accord.
"I am immensely proud that we have brought in this new route for Hong Kong BN(O)s to live, work and make their home in our country," Prime Minister Boris Johnson said in a statement.
"In doing so we have honoured our profound ties of history and friendship with the people of Hong Kong, and we have stood up for freedom and autonomy -- values both the UK and Hong Kong hold dear."
Any Hong Kong resident born before 1997 is eligible for BN(O) status. The new visa path opens up entry to the UK to an estimated 2.9 million adults in Hong Kong and another 2.3 million of their dependants.
In practice, London projects that up to 322,400 of Hong Kong's 7.5 million population will take up the visa over five years, benefiting the UK economy by up to £2.9 billion ($4 billion).
The new pathway will not come cheap.
A five-year visa will cost a relatively moderate £250 per person. But a mandatory surcharge to access Britain's state-run health service will run to £3,120 per adult, and £2,350 for those under 18.
Shorter, cheaper visas for 30 months will also be available.
"We have been clear we won't look the other way when it comes to Hong Kong. We will live up to our historic responsibility to its people," Foreign Secretary Dominic Raab said.
"China's imposition of the National Security Law in Hong Kong constitutes a clear and serious breach of the (pre-handover) Sino-British Joint Declaration contrary to international law."
The security law was imposed on Hong Kong last June in response to 2019 protests, targeting acts Beijing deems to be secession, subversion, terrorism or collusion with foreign forces.
Mass arrests of pro-democracy figures have followed. Some have fled Hong Kong for the West, including to Britain.
Between July and this month, about 7,000 people with BN(O) status and their dependants have already been given exceptional leave to live in the UK.
China, furious at Britain's new visa pathway, has in turn accused London of flouting the handover agreement and demanded Western countries stay out of Hong Kong's affairs.