The British authorities have reportedly demanded that Beijing explain "greyed out" areas in the layout of the massive compound

Plans for China's so-called "super embassy" in London have been delayed after UK officials demanded clarification over "greyed-out sections" of its design and Beijing refused to disclose further details, according to the Financial Times. China has slammed the move.

The project, dubbed a "super embassy" in British media, would be the largest such compound in Europe. It has faced multiple bureaucratic setbacks since Beijing first applied for a permit in 2022.

On Saturday, a spokesperson for the Chinese embassy in the UK voiced "serious concern" over the Ministry of Housing, Communities and Local Government's postponement, saying Beijing had followed all "customary diplomatic practices" and relevant procedures in its application and had provided comprehensive answers to the questions posed by British officials.

"It is an international obligation of the host country to provide support and facilitation for the construction of diplomatic premises," the spokesperson stated, noting that the UK is also planning to erect a new building for its own embassy in Beijing.

On Friday, the Financial Times reported that Beijing had refused to "identify... the rationale and justification" for the "greyed out" Cultural Exchange Building and Embassy House in the compound layout, despite a request from Housing Secretary Angela Rayner.

Chinese officials said Wednesday they did not deem it "necessary or appropriate to provide full internal layout plans... in order to understand what has been permitted," according to the FT.

The Ministry of Housing soon thereafter said it would delay the decision on the application until October 21.

China bought the five-acre Royal Mint Court site near the Tower of London in 2018. Beijing has since sought to build an embassy complex there, which is expected to be ten times larger than the diplomatic mission's current premises. Aside from the main building, it would encompass offices, 225 homes, and a cultural exchange center, according to media reports.

Critics have argued that China could use the "super embassy" for covert surveillance activities.

In recent years, London and Beijing have repeatedly traded allegations of espionage.