China has moved to block the UK’s offer of citizenship to Hong Kong residents, warning it may not recognise their passports as valid documents.

Beijing hit out after the government said it would “welcome warmly” any of 2.9 million Hong Kongers with British National Overseas (BNO) status, who fear its crackdown in the territory.

The move appears to confirm the fears of Dominic Raab, who said last weekend: “Ultimately, if they follow through on something like that, there would be little we could do to coercively force them.”

It comes after the UK suspended its extradition treaty with Hong Kong in response to China’s draconian new national security law which it called “a clear and serious violation” of the agreement for the territory.

Mr Raab, the foreign secretary, warned the arrangement – which has been in place for more than 30 years – would lead to dissidents being sent on to China.

The warning that UK passports might not be recognised came in an announcement by China’s foreign ministry.

A spokesman said the UK’s visa offer meant its “previous assurances are no longer valid” and accused it of “politically manipulating” the issue.

“It has broken its promises and violated international law and basic norms,” the spokesman said, adding: “So China will consider not recognising BNO as aa valid travel document.”

London is offering the ability to come to Britain to anyone who received BNO status at the time Hong Kong was handed over from the UK to China in 1997.

They will be entitled to move with their spouse and any children living at the same home as them, even if the children are over 18.

They will not need to have a job offer or demonstrate a particular skill level, but once in the UK they will have to support themselves without being eligible for benefits.

And Priti Patel, the home secretary, has been criticised because no-one under the age of 23 – including many who have led anti-Communist protests – will be able to come to the UK.

She told MPs: “BNO citizens will need to ask themselves whether coming to the UK to put down roots here is the right choice for them. It is a choice I am making available and I welcome warmly all those who decide to take it.”.

The cost of the new visa – coming into force in January – has not been set but is likely to be many hundreds of pounds.

And all those who claim it will also have to pay the new, higher £624-a-year charge for the immigration health surcharge, supposedly to use the NHS.

After five years, they can apply for settled status at a cost of £2,389, then after another year they can pay £1,206 for citizenship.