LONDON — China has triumphed in its long-running battle to build a new mega embassy in London. Its opponents are already in fightback mode.

Housing Secretary Steve Reed on Tuesday approved plans for the 20,000 square meter complex near the Tower of London days before U.K. Prime Minister Keir Starmer is expected to visit China to boost economic and diplomatic ties with Beijing.

But with MPs across the spectrum still harboring concerns about the project — from the potential for espionage, to the targeting of Hong Kong and Uyghur exiles who have sought sanctuary in the U.K. — Tuesday’s decision is unlikely to mark the end of the saga.

A local residents’ group opposed to the embassy is lining up senior lawyer Charles Banner, who has previously advised the U.K. government on different planning matters, to mount a legal challenge.

And some of the prime minister’s own Labour Party lawmakers are considering offering their support, given it is realistically the only route left for them to oppose the plan.

“The decision is now final unless it is successfully challenged in court,” Reed said in a statement announcing the decision on Tuesday.

“MPs will be supportive of legal review,” said one Labour MP, granted anonymity to speak candidly about internal party discussions, said.

“Many people, including ministers, are very uncomfortable on our side,” another MP added.

In the House of Commons, critical MPs have repeatedly raised concerns about Chinese espionage efforts.

They have highlighted reports that one of the dozens of secret rooms beneath the sprawling complex at Royal Mint Court would be a secret chamber sitting directly beside fibre-optic cables that not only transmit financial data to the banks of the City of London, but email and messaging traffic for millions of the capital’s internet users.

The U.K. housing ministry said in a letter accompanying the decision that there is “no suggestion” the development will interfere with the cables.

With allies of U.S. President Donald Trump also voicing concerns about the plan, there remain diplomatic dangers ahead for the U.K. government in approving China’s plans.

In an interview published Sunday Speaker of the U.S. House of Representatives Mike Johnson said security concerns over the embassy “seem real to us.”

The Trump administration has raised concerns with British diplomats behind the scenes, according to one U.K. official, granted anonymity like other officials quoted in this piece because they are not authorized to speak on the record. “They have been clear on their objections,” they said.

The road to approval

China bought the vast site that once smelted British currency for £255 million back in 2018, under its plans for a grand expansion from its existing mission.

The project was thwarted in 2022 when Tower Hamlets Council, the local authority responsible for granting planning permission, rejected its first application to develop the site, citing safety and security concerns.

Beijing was furious, and sought to apply political pressure on the then-Conservative government.

There remains suspicion that the U.K.’s own request to rebuild the British embassy in Beijing, which is “falling to pieces,” is being blocked in a tit-for-tat battle, according to a former senior official.

Intermittent water supply problems at the U.K.’s Beijing embassy have been seen by some in London as an attempt to apply political pressure.

“They thought what they needed to do was hold us to ransom —give us the planning for ours otherwise we won’t let you do yours in Beijing,” the former official said.

After Starmer’s Labour Party won the U.K. general election in July 2024 China resubmitted the embassy plans without significant changes, and in October that year ministers “called in” the plans to make a quasi-judicial decision. 

Before the decision was made, the Chinese Foreign Ministry warned Britain would “bear all consequences” if it was rejected.

That decision was published on Tuesday ahead of Starmer’s long-planned trip to China.

Reed stressed the “quasi-judicial” decision had been made “fairly, based on evidence and planning rules.”

Legal threats loom 

But a local residents’ association opposed to the embassy plan has already indicated it plans to request a judicial review.

It is fundraising for its legal challenge, and hopes to lodge an appeal within weeks of the government decision.

Mark Nygate, treasurer of the Royal Mint Court Residents’ Association, which represents 100 leaseholders who live in neighboring apartments, said: “We are going to have to fight our corner and attempt to do a judicial review.

“We’re really concerned about our safety and privacy — and whether we’ll be moved off the land,” the 65-year-old added.

The group is unlikely to apply for a review before Starmer returns from China, as they will first have to comb through the report published with the decision.

Nygate said the group is considering arguing the decision was “pre-determined” by the government before the review. Ministers deny any political interference. 

But one option the group has, Nygate explained, is to point to Starmer’s remarks, caught on camera during his first meeting with China’s Xi Jinping on the sidelines of the G20 summit in Brazil in November 2024, in which the U.K. PM noted that the Chinese president had raised the embassy with him during their August 2024 phone call.

“And we’ve since taken action by calling in that application — now we have to follow the legal process and timeline,” the PM said. 

Nygate said: “All along the line it seems the government’s finger prints have been on this.”

Banner, who, according to two people involved in legal challenge plans, is being lined up to lead the action, has previously advised the government on how to reduce the time a judicial review can take on infrastructure projects.

Yet even if the residents’ legal challenge is unsuccessful, the judicial review could still prevent building work starting for years as the challenge makes its way through the courts.

With all Labour’s main political rivals opposing the embassy, the political climate could change after August 2029 — the deadline for the next general election.