Britain still needs economic co-operation with China but will take “strong” action against any national security challenge, Yvette Cooper said, after it emerged an alleged spy formed links at the heart of the British establishment.

The Home Secretary said the UK has a “complex” relationship with Beijing as she was questioned about concerns over a businessman who is now banned from the country but previously became close with the Duke of York.

The alleged agent, known only as H6, also met former prime ministers Lord David Cameron and Baroness Theresa May and kept pictures of them in his London office, according to reports.

Asked what her message would be to the Chinese state following the case, Ms Cooper told the BBC’s Sunday With Laura Kuenssberg programme: “We will continue to take a very strong approach to our national security, that includes to any challenge to our national security including to our economic security from China, from other countries around the world, that will always be the approach that we will take.

“Of course, with China we also need to make sure we have that economic interaction, economic co-operation in place as well. So it’s a complex arrangement.”

The alleged spy, known only as H6, was described in court as having formed an “unusual degree of trust” with the duke.

Reports suggest he met Lord Cameron at a Downing Street reception and Lady May at a black-tie event.

The alleged spy was excluded from Britain in 2023 by then-home secretary Suella Braverman, with the Home Office saying he was believed to have carried out “covert and deceptive activity” for the Chinese Communist Party.

Judges at a specialist tribunal in London on Thursday ruled Ms Braverman had been “entitled to conclude” that he “represented a risk to the national security” after he challenged the decision.

Shadow home secretary Chris Philp described alleged activities carried out by Beijing in the UK were “deeply concerning” and need “looking at very carefully”.

He urged everyone in public life, academia and business to be “alert” to the risks of infiltration.

“If anyone has the slightest concern, they should contact the security services immediately,” he said.

Home Office minister Dame Angela Eagle said the man had been thought to pose a threat “especially in his relationship with Prince Andrew” which is why he was barred from coming to the UK.

But she downplayed the significance of the suspect being pictured with former prime ministers, telling Sky News’ Sunday Morning With Trevor Phillips that “photographs aren’t necessarily any more meaningful than photographs”.

Asked whether the revelations about the alleged spy’s relationship with Andrew were an embarrassment for the UK, Dame Angela said: “I’m not going to comment on the internal issues with the royal family. I don’t think that’s appropriate.

“Everybody knows what’s happened. They know the actions that’s been taken and they can come to their own judgment.”

MPs have raised concerns about the level of access the businessman was apparently able to gain at the heart of the British establishment.

Nigel Farage has said his Reform UK party is prepared to use parliamentary privilege to name the individual, whose identity is protected by a court order, in the Commons chamber.

Former Tory leader Sir Iain Duncan Smith, a prominent China hawk who has himself been sanctioned by Beijing, said the duke needs to be “clear and honest” about what happened and called for a “full, proper investigation” by the security services.

Baroness Harriet Harman said the Government, parliamentarians, the royal family and society more widely need to “up our game” in spotting the potential threats in relation to China.

The former Labour minister told Sky News’s Sunday Morning With Trevor Phillips programme: “We seem to have a bit of a sort of ignorant spot in relation to China, both what the opportunities are and what the threats might be.

“And I think that’s something, generally speaking, amongst parliamentarians, amongst Government, amongst ordinary people as well as the royal family we need to up our game on… and be more understanding of what’s going on in China and what their objectives might be, and what that might mean for us, for good or ill.”

Labour peer Baroness Harriet Harman said the Government, parliamentarians, the royal family and society more widely need to “up our game” in spotting the potential threats in relation to China.

“We seem to have a bit of a sort of ignorant spot in relation to China, both what the opportunities are and what the threats might be,” she said.

The businessman had brought a case to the Special Immigration Appeals Commission (SIAC) after his initial exclusion in 2023, but his appeal was dismissed on Thursday.

At a hearing in July, the tribunal was told that an adviser to Andrew had said he could act on the duke’s behalf when dealing with potential investors in China, and that H6 had been invited to the duke’s birthday party in 2020.

A letter referencing the event from the aide, Dominic Hampshire, was discovered on H6’s devices when he was stopped at a port in November 2021.

The letter also said: “I also hope that it is clear to you where you sit with my principal and indeed his family.

“You should never underestimate the strength of that relationship… Outside of his closest internal confidants, you sit at the very top of a tree that many, many people would like to be on.”

On Friday, a statement from the duke’s office said: “The Duke of York followed advice from His Majesty’s Government and ceased all contact with the individual after concerns were raised.

“The duke met the individual through official channels with nothing of a sensitive nature ever discussed.

“He is unable to comment further on matters relating to national security.”

A spokesman for Lady May said: “Baroness May and her husband, Sir Philip, are photographed at numerous events in any given year; as such, she doesn’t remember when or where this particular photograph was taken or the man in question.”

A representative for Lord Cameron has been contacted for comment.