A London-based Hong Kong pressure group will picket the offices of the UK Government’s Foreign and Commonwealth Office in London on Sunday, following the department’s response to the Lee Po kidnapping as a “serious breach” of the Sino-British Joint Declaration. Organisers Brits For Hong Kong said London was in a position to declare the 1984 Sino-British Joint Declaration “null and void,” and subsequently make new arrangements for self-rule to be established in the SAR. TIMELINE: Hong Kong’s missing booksellers and what we know so far Last week, Britain produced its strongest statement concerning Hong Kong’s situation in its latest six-monthly healthcheck of the city. Britain called the “involuntarily removed” missing bookseller Lee Po a “serious breach” of the Sino-British Joint Declaration. The renewed diplomatic tension over Lee comes as the UK government expressed “serious concern” over the level of rights and freedoms enjoyed by Hongkongers, claiming they had come under “unprecedented pressure”. READ MORE: Lee Po ‘involuntarily removed’ from Hong Kong to mainland China, says UK government Jack Hazlewood, 17, one of the group’s co-founders, insisted the British public cared about Hong Kong’s colonial past, its present situation and its future. “We want to send a message to the UK Government that there are lots of British voters who genuinely care about Hong Kong, and that Hong Kong is well and truly a British issue,” he said. The student explained Brits For Hong Kong was about “giving members of the British public a chance to show their support for Hong Kong. We hope that it can become a rallying point for people here in the UK who are concerned about Hong Kong.” The group said it was expecting upwards of 100 supporters. Demonstrations against Hong Kong issues normally appear outside the Chinese Embassy in the British capital. Brits for Hong Kong have written a letter to Foreign Secretary Philip Hammond urging the government to intervene.