A letter written to interested parties by the government department responsible for weighing the request showed that the housing minister has pushed the deadline back to January 20.

"We aim to issue the decision as quickly as possible," said the letter, released by the Inter-Parliamentary Alliance on China (IPAC).

Residents, rights groups and China hawks from across the UK political spectrum oppose the development, which, if approved, would become the largest embassy in the UK.

They fear the site could be used to surveil and harass dissidents.

A spokesman for Starmer suggested that "particular security implications" meant that more time was needed to consider the planning application.

"The Home Office and Foreign Office have provided views on particular security implications, and have been clear throughout that a decision shouldn't be taken until we affirm that those considerations have been completed or resolved.

"MHCLG (the Ministry of Housing, Communities and Local Government) considers that more time is needed for full consideration of the applications," he told reporters.

Housing minister Steve Reed had previously extended the deadline to December 10.

The decision is viewed as a key issue in Starmer's attempted reset of relations with China, which remain strained by accusations of spying and by tensions over the fate of Hong Kong, a former British colony.