By Greg Torode and James Pomfret

HONG KONG, Feb 19 (Reuters) - One of Hong Kong's most experienced judges has warned that a storm over the rule of law has "broken out in full force" in the protest-hit Asian financial hub, urging people to treasure the system.

In a rare comment, Justice Kemal Bokhary of the city's highest court, the Court of Final Appeal, built on a high-profile 2012 statement that a legal storm of "unprecedented ferocity" threatened the former British colony.

"If that storm broke out, I said, our judiciary would stand up in it - doing so with the support of our people," he wrote at the start of a recently-published legal text.

"The storm has broken out. It has broken out in full force. I remain confident that our judiciary will do its impartial duty."

His remarks come amid fears in legal and diplomatic circles about pressure from Beijing's Communist Party leadership on Hong Kong's independent judiciary, as well as fierce criticism of some judges and their rulings amid sometimes violent tension that has gripped the Chinese-ruled city.

Student-led protests that began last June over a bill, now scrapped, to extradite people to mainland China have since morphed into wider demands, including full democracy. The unrest has led to three successive quarters of economic contraction.

Nearly 23 years since Hong Kong was returned to China under a "one country, two systems" framework, the judiciary is seen as one of the last bastions of its freedoms and autonomy.

The health of the system, which remains part of the British-based common law tradition, is widely seen as vital to the city's role and reputation as an international financial hub.

With thousands of cases pending, both pro-Beijing figures and anti-government protesters have criticised the courts.

Late last year some demonstrators lobbed petrol bombs near the Court of Final Appeal and sprayed graffiti on the High Court.

Bokhary wrote of divergent community views on who was "to blame for the blows now being rained down on the rule of law".

"What a court does in any given case may be as unwelcome to one section of the community as it is welcome to another," he said in the comments, dating from October.

Making "wild allegations" against the court harmed the rule of law, he added.

Bokhary's remarks figure in a brief preface to the 2020 edition of the leading work on Hong Kong's criminal law and practice, a 2,081-page volume known as Archbold Hong Kong.

Published in December by Sweet & Maxwell, part of Thomson Reuters, the book has circulated more widely in recent months.

Bokhary has served as its editor-in-chief for the last decade but has not been as strident in previous editions.

Although he retired in 2012 from his role as a full-time judge on the court, Bokhary remains a non-permanent judge.

Contacted by Reuters, he declined to elaborate on precisely what inspired his warning, but added he was confident that Hong Kong's judiciary could withstand the storm he described.

Chief Justice Geoffrey Ma, who heads the court, declined to offer any comment on Reuters' enquiry.

In a rare speech last month, Ma urged efforts to protect Hong Kong's legal system, saying that once it was damaged, "This is not something from which our community can easily recover."

Prominent commercial lawyer and commentator Kevin Yam said the remarks had raised eyebrows in legal circles but showed that, despite widespread concern, Hong Kong's judicial independence was being staunchly defended.

"We can see at least there are a lot of people working hard to hold the line," he said. (Reporting by Greg Torode and James Pomfret in HONG KONG; Editing by Clarence Fernandez)

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