The Legal Aid Department has repeatedly used the wrong test to assess whether or not to fund civil cases, raising concerns that the poor have been denied access to justice.
A recent High Court judgment showed the department had required a case to demonstrate a more than 50 per cent chance of success to qualify for legal aid, rather than a "reasonable chance of success", as written in the legal aid ordinance.
The incorrect test was adopted despite at least two earlier judgments ruling that the over-50 per cent threshold was wrong - one in 2012 and one as far back as 1999.
The correct test is even stated on the department's website.
Lawmaker James To Kun-sun, who is also a solicitor, said: "I can't understand why the Legal Aid Department keeps applying the wrong test again and again. It just does not respect the law and earlier decisions made by the courts.
"It is a straightforward test," he added. "Legal aid is too important a support for the poor who may be fighting the government and the powerful and the rich."
He called on the department to investigate the error and make sure it did not happen again.
University of Hong Kong law professor Michael Davis said: "The provision of legal aid is fundamental to access to justice."
Statistics show there were 16,533 legal aid applications for civil cases in 2012, of which 8,171 were granted funding. Between July and September last year, 1,821 out of 4,076 legal aid applications were successful.
The Legal Aid Department declined to respond to inquiries about how many applications had been rejected for failing to meet a chance-of-success requirement of more than 50 per cent. A spokesman said it could not comment as legal proceedings were continuing.
The error came to light in the case of Chung Yuk-ying, who was injured while delivering documents. She had been denied legal aid for a civil claim against a man who allegedly tripped her up, his employer and the property management company of the building where the incident occurred.
Chung appealed to a High Court master - who deals with procedural matters - and argued that the department and the barrister applied the wrong test.
The master dismissed Chung's appeal, but the High Court papers on that judgment show that a legal aid department lawyer had referred to a handbook used in England to argue a "reasonable chance" meant a chance higher than 50 per cent.
Under section 10(3) of the Legal Aid Ordinance, a person should not be granted legal aid unless he shows "reasonable grounds for taking, defending, opposing or continuing such proceedings or being a party thereto".
Chung has now been granted permission to lodge a judicial review of the master's decision by Madam Justice Queeny Au Yeung Kwai-yue, of the Court of First Instance.
"The court does not have to be satisfied that it is more probable than not that the issue of fact will be decided in the appellant's favour," Au wrote. "But it has to be satisfied that the appellant has shown that there is a 'reasonable, as opposed to a fanciful, chance of the court at trial deciding that issue of fact in his favour'."