The government has been warned it faces an "embarrassing and potentially catastrophic" legal challenge if it approves plans for a new Chinese “super-embassy” in London.
MPs across the whole political spectrum have urged the government to reject the controversial proposals for the building at Royal Mint Court near the Tower of London, citing national security concerns and fears the site could be used for espionage.
Last week, around 100 people gathered at the site to protest against the plans as Kemi Badenoch and Sir Iain Duncan Smith took to the stage as guest speakers at the event.
The Government is set to decide whether to give the proposals the green light today, with China threatening Britain with “consequences” if they are not approved.
Campaigners have vowed to push ahead with their fight against the embassy, with local residents raising money to launch a judicial review.
Luke de Pulford, head of the Inter-Parliamentary Alliance on China, said the Government faced an "embarrassing and potentially catastrophic" legal challenge if the plans were approved.
"Years of campaigning about the obvious and manifold risks posed by this embassy development have not been enough to outweigh the UK Government's desire for Beijing's money,” Mr de Pulford said.
"The fight isn't over.
"The campaign now heads to the courts where the Government is about to become embroiled in an embarrassing and potentially catastrophic judicial review."
The Ministry of Housing, Communities and Local Government (MHCLG) is widely expected to give the plans the go-ahead, though ministers have declined to comment on the process ahead of the formal decision being made.
Ciaran Martin, former chief executive of GCHQ's National Cyber Security Centre, last week dismissed concerns about the proposed embassy's proximity to data cables said to be crucial for financial sector communications between the City of London and Canary Wharf.
In an article for the Times, he said the plans would have been thoroughly scrutinised by the UK's security services, and that "no Government would override their advice were they to say the risks were too great".
However, MPs including from within Labour ranks have warned that the embassy could also be used to "step up intimidation" against dissidents and have urged Communities Secretary Steve Reed to block the application.
The Government has argued that it would consolidate Chinese diplomatic presence from seven buildings to one, which could have security benefits.
Addressing the Commons on the eve of the decision deadline, Foreign Office minister Seema Malhotra said: "We've been consistently clear that national security is the first duty of Government, and it has been our core priority throughout the embassy process, with the close involvement of the security and intelligence agencies."
She said a "range of measures" had been implemented to protect national security and that she had "full confidence" in the security services to be able to manage potential risks from spies.
