The National People's Congress has written to British lawmakers telling them ties between the two nations are at risk unless they stay out of Hong Kong's affairs.
The foreign ministry in Beijing confirmed the warning yesterday, as the lawmaker heading a British inquiry on Hong Kong said the central government may have breached the terms of the 1984 Sino-British Joint Declaration when it set rules for democratic elections in 2017.
But the lawmaker, Richard Ottaway, admitted Britain was in a "weak" position when it came to admonishing China for a breach of the deal that settled Hong Kong's future and paved the way for the 1997 handover.
The debate arose after the NPC Standing Committee set a framework for political reform under which only two or three candidates could run in the first one-man, one-vote election for chief executive in 2017. They would need support from half of the members of a nominating committee expected to be dominated by Beijing loyalists.
Ministry of Foreign Affairs spokesman Qin Gang said in Beijing that the NPC's Foreign Affairs Committee had written the letter, while ambassador to London Liu Xiaoming also conveyed China's views to the lawmakers.
"Issues concerning the political reform of Hong Kong fall into China's domestic affairs, which allow no interference from the outside," he said. "It is justifiable for the Chinese side to express its solemn position on this issue."
The House of Commons Foreign Affairs Committee, chaired by Ottaway, announced an inquiry into Britain's relations with Hong Kong in July. Ottaway confirmed to the Post yesterday that Liu raised objections later that month, and that the letter urging it to drop the probe had followed two weeks ago. The letter advised committee members to "bear in mind the larger picture of China-UK relations".
The lawmakers are examining the implementation of the Joint Declaration, which states that Hong Kong should have a high degree of autonomy and executive power, and that personal rights in the territory must be enshrined by law.
Ottaway said Beijing's ruling on reform appeared to have breached those undertakings."If you have a committee that is not neutral and is nominating a limited number of candidates, there seems to be a prima facie case that the undertakings given have been breached," Ottaway told the BBC.
But he admitted Britain had little leverage with Beijing.
"As far as sanctions are concerned, frankly we are in a fairly weak position. Indeed, we were in a very weak position right from the beginning when this declaration was signed," Ottaway said.
In July, British Deputy Prime Minister Nick Clegg said Britain would honour its 1984 pledge to "mobilise the international community and pursue every legal and other avenue available" if China breached the deal.
But other members of the British government are eyeing Chinese investors and tourists and attempting to rebuild ties after Prime Minister David Cameron met the Dalai Lama in 2012.