Sino-British relations have been dealt a fresh blow after the Chinese government announced it will no longer recognise the British National (Overseas) passport as a valid travel document or form of identification.

The decision was announced days before a new visa route for Hong Kong nationals looking to move to the UK is due to open.

The Foreign, Commonwealth and Development Office (FCDO) said it was “disappointed but not surprised” by the decision.

Prime Minister Boris Johnson said the visa scheme – which was announced in the wake of Beijing’s national security law being imposed on Hong Kong last year – honours the “profound ties of history and friendship” between the UK and its former colony.

Under the scheme, Hong Kong residents and their dependents would be offered a route to residency and eventual citizenship in the UK, with an estimated 300,000 Hongkongers expected to take advantage of it.

The British side’s attempt to turn a large number of Hong Kong people into second-class British citizens has completely changed the nature of the two sides’ original understanding of BN(O)

But the announcement by Chinese foreign ministry spokesman Zhao Lijian throws new uncertainty around the plan just hours after the UK said it would begin taking applications for BN(O) visas from Sunday.

Mr Zhao told reporters at a daily briefing: “The British side’s attempt to turn a large number of Hong Kong people into second-class British citizens has completely changed the nature of the two sides’ original understanding of BN(O).

“This move seriously infringes on China’s sovereignty, grossly interferes in Hong Kong affairs and China’s internal affairs, and seriously violates international law and the basic norms of international relations.”

Responding to the announcement, the Prime Minister’s official spokesman said: “We have been clear that we will not look the other way when it comes to Hong Kong people with British National (Overseas) status who now have a choice to come and live and work and study in the UK.

“And it remains the case that BN(O)s and their families can use documentation other than BN(O) passports to travel and enter the UK.”

An FCDO spokesman said: “We are disappointed but not surprised by the Chinese decision not to recognise British National (Overseas) passports.

“Despite China’s announcement, BN(O)s and their families will be able to use documentation other than BN(O) passports to take up this visa.

“People with BN(O) status now have a choice to come and live, work and study in the UK. We look forward to welcoming those who wish to settle here.”

Labour MP Shabana Mahmood said: “The Foreign Secretary must make clear what action he is taking to protect the historic rights of Hong Kong BN(O) passport holders.

“A truly global Britain should be standing up for those who want their democratic rights protected.”

Conservative MP Michael Fabricant said: “So much for treaty obligations to respect the citizenry rights of Hong Kong.”

The BN(O) status was created before the UK handed responsibility for Hong Kong back to China in July 1997.

The new visa route is seen as significant because it offers Hongkongers the chance to move to the UK and gain citizenship.

Under the new scheme, those with BN(O) status will be eligible for UK visas, then, after five years, they will be able to apply for settlement, followed by British citizenship after a further 12 months.

The Prime Minister said: “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.

“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.”

The UK has previously expressed concern about mass arrests of pro-democracy politicians and activists in Hong Kong following the introduction of strict new security laws by the Chinese government.