Former British governor Chris Patten hit out at Beijing's white paper on Hong Kong, saying it was "wholly reasonable" for Hongkongers to protest.
In an interview with the Financial Times, Patten said Hong Kong judges should not be subject to political considerations, referring to a statement in the document that judges are administrators and as such have a "basic political requirement" to love the country.
The paper, which outlines its "comprehensive jurisdiction" over the city, also states that judges are responsible for "correctly understanding and implementing the Basic Law".
Patten has seldom spoken out on Hong Kong issues since the handover, but he told the newspaper he felt compelled to do so because of the white paper.
"Judges under the rule of law are independent and there shouldn't be any question of them being instructed or pressed to subordinate their views of due process and what is legal to some other political considerations," he was quoted as saying.
Patten said the document suggested that the Sino-British Joint Declaration, which paved the way for the city's handover to China in 1997, was not "joint". "The Joint Declaration was an international agreement … between China and Britain, guaranteeing Hong Kong's freedoms and pluralism under the rule of law for 50 years," he said.
"It is wholly reasonable for Hong Kong citizens to express concerns to both signatories if they think the terms of that Joint Declaration are being questioned or undermined."
He also expressed surprise that business groups had not voiced opposition to the paper.
"It is surprising that professional bodies … appear to have taken the line that they have publicly," he said. "I can only assume that they haven't had the agreement of their global headquarters for what they have been saying. I would imagine that their global heads would have been surprised and slightly embarrassed."
British Prime Minister David Cameron did not comment on the paper last month when Premier Li Keqiang was in London. Asked if Cameron should criticise it, Patten said he didn't know what was discussed.