Hong Kong's prosecutors will be given more opportunities to appeal against any acquittals in national security trials, under new legislation planned by the government.

In a statement on Tuesday, the Department of Justice (DOJ) explained that at present, prosecutors do not have the right to turn to the Court of Appeal if a three-judge Court of First Instance panel acquits a defendant in a national security trial, "even though its reasons for verdict may disclose an error of law".

This contrasts with acquittals by magistrates or District Court judges, which can be subject to appeal under existing law.

Another change planned to the Criminal Procedure Ordinance will give prosecutors the ability to appeal if the judge in a High Court criminal trial with a jury rules the defendant has no case to answer.

“The proposed new statutory appeal mechanisms are necessary, legitimate and timely responses to address lacunae in the criminal appeal system due to the prosecution's inability to appeal against any no-case rulings and acquittals by professional judges of the CFI that are erroneous, so as to prevent possible miscarriage of justice,” the DOJ said.

“The legislative amendments under the two proposals, being procedural in nature, will apply to rulings, verdicts or orders given after the legislative amendments come into operation. The bill does not undermine a defendant's right to a fair trial, and does not contravene the principle against double jeopardy.”

Law Society President Chan Chak-ming expressed support for the proposed amendments, saying they are reasonable and appropriate from a policy perspective.

He said both the prosecution and the defence should have the right to appeal if a ruling is believed to be flawed.

The amendment bill is set to be gazetted on May 25, with its introduction into the Legislative Council scheduled for May 31.