China on Tuesday accused London of interfering in its domestic affairs, over a British parliamentary inquiry into democratic reforms in its former colony Hong Kong. The public rebuke followed reports Monday that Chinese authorities had written to the parliamentary foreign affairs select committee to demand the probe be dropped. "Hong Kong has returned to the motherland," China's foreign ministry spokesman Qin Gang said Tuesday. "Hong Kong is a special administrative region of China. Issues concerning the political reform of Hong Kong falls totally within China's domestic affairs, which allows no interference from the outside." Gang said British MPs had "addressed inquiries" to China on the implementation of the Sino-British Joint Declaration, which set out arrangements for the 1997 transfer of Hong Kong to Chinese sovereignty. "It is justifiable for the Chinese side to express our solemn position on this issue," Qin added at a regular press briefing in Beijing. His comments followed a BBC report Monday which said it had seen a letter from a Chinese committee condemning the probe and describing as a "highly inappropriate act which constitutes interference in China's internal affairs". The report also said the Chinese Ambassador to London had tried to "warn MPs off", and Qin confirmed Tuesday the diplomat "has also expanded on China's position to the British side". The deal that handed Hong Kong back to China guaranteed some freedoms and a semi-autonomous status, and the British foreign secretary reports to parliament on the territory every six months. Pro-democracy activists in Hong Kong are vowing to launch a campaign of civil disobedience over Beijing's decision to vet candidates for the city's next leadership election. Critics have described the restrictive framework on elections announced on Sunday by the National People's Congress, China's rubber-stamp legislature, as a betrayal of Beijing's promise to award Hong Kong universal suffrage by 2017. The chairman of the British Foreign Affairs Committee, which oversees the work of the Foreign and Commonwealth Office, told the BBC he wanted to avoid any misunderstanding. "My job and the Foreign Affairs Select Committee's job is to look at whether Britain has complied with its undertakings, and if China has not complied with its obligations," Richard Ottaway said. "I think this is a right and proper procedure. I don't particularly want to irritate the Chinese. I want them to understand the procedure. "It may well be that my committee will decide that actually the Chinese have behaved perfectly reasonably."