Significant security concerns have been raised over the site’s proximity to cables carrying communications to the City of London financial district, and Beijing’s refusal to present full internal layout plans to British authorities.

Britain this week pushed the deadline for a final ruling on the building from Oct. 21 to Dec. 10, prompting “grave concern and strong dissatisfaction” from Beijing.

Lin told a press conference in China Friday that the country had displayed “the utmost sincerity and patience” during talks over the site, and accused Britain of showing “disregard for contractual spirit, acting in bad faith and without integrity.”

A decision was initially due by Sept. 9 after ministers took control of the application from Tower Hamlets Council in London, making this the second delay by the British government.

The delay comes in a particularly sensitive week for U.K.-China relations. Prime Minister Keir Starmer has faced pressure over the collapsed prosecution of two men accused of spying for China.

Lin demanded Britain “immediately fulfill its obligations and honor its commitments … otherwise the British side shall bear all consequences.”