The UK government is expected to approve China’s plans for a new mega embassy in central London.

A final decision has not yet been formally taken, but the advice ministers are understood to have received from the intelligence agencies clears the path for the controversial project to be given the go ahead.

The expected green light – first reported by the Times newspaper – will become the latest case study in the growing public argument about how wise a close relationship with Beijing is.

The approval or rejection of the planning application lies with the Housing Secretary Steve Reed – in what is known as a quasi-judicial decision.

But given the sensitivities of this judgement call, many others have been consulted – including MI5 and MI6.

The decision has repeatedly been delayed and last month the government pushed back a deadline to rule on the application to 10 December.

The site at Royal Mint Court is close to the City of London, and fibre optic cables that carry vast quantities of highly sensitive data, sparking concerns it could pose an espionage risk.

The embassy, at 20,000 square metres, would be the biggest of its kind anywhere in Europe.

Some have argued that a single site, rather than multiple sites across London, may be easier to manage and there is an awareness in government that rejecting China’s long-standing desire for its new embassy could set back diplomatic relations.

However, Conservative shadow foreign secretary Dame Priti Patel warned that approving the embassy would put Britain at risk, accusing Prime Minister Sir Keir Starmer of being “desperate and unprincipled”.

The Chinese Embassy in the UK has previously said the new complex would enhance “mutually beneficial cooperation” between China and Britain, with officials arguing objections to the site are unjustified.

Since winning the general election last year, Labour has sought to thaw the UK’s relationship with Beijing.

Chancellor Rachel Reeves, Business Secretary Peter Kyle and the most senior civil servant in the Foreign Office, Sir Olly Robbins, have all been on visits to China.

The prime minister is expected to make his own trip to the country, perhaps as soon as early next year.

Asked about the prospect of heading there, he told reporters en route to the G20 Summit in Johannesburg, South Africa, that no visit was confirmed yet.

He said the government’s approach to China “is the same approach as we’ve always taken, which is cooperate where we can and challenge where we must, particularly on national security”.

Critics say the government is insufficiently hard-headed about what they see as the threat posed by Beijing, and argue for a much greater caution in the UK’s relationship.

Dame Priti said: “It beggars belief that Starmer is jetting off to Beijing just months after the case against the alleged Chinese spies collapsed on his watch.”

She added: “Keir Starmer is so weak, and our economy so precarious, that Labour feels it must kowtow to China at every opportunity, regardless of the cost to our country.”

In September a case involving two men – including a former parliamentary researcher – who were accused of spying for China collapsed in controversial circumstances. Both men denied wrongdoing.

Prosecutors said the case was dropped because they could not get evidence from the government referring to China as a national security threat.

However, ministers insisted they were frustrated it collapsed and blamed the position of the previous Conservative government, as well as out-of-date national security legislation.

Earlier this week MI5 issued an alert to MPs and peers, warning they faced a significant risk of spying from the Chinese state.

The alert said individuals working on behalf of the Chinese Ministry of State Security were posing as “headhunters” on platforms like LinkedIn and targeting people working in British politics to obtain insider information.

China has rejected claims of espionage as “pure fabrication”.