Civil service minister Ingrid Yeung on Friday says tens of thousands of government workers could be called up to deal with major incidents, with practice drills to begin early next year.

Speaking on an RTHK radio programme, Yeung said officials were working on implementing a plan announced in last week's Policy Address for "government-wide mobilisation" that goes beyond existing mobilisation protocols. It would go into effect in the event of major incidents such as natural disasters or public health emergencies, like the pandemic.

"We are aiming at mobilising staff up to tens of thousands for mega incidents that require a lot of staff input, a lot of immediate staff response," Yeung told reporters after the radio programme.

"We are hoping to be able to do some drills in the first quarter of next year."

The minister said the number of staff to be mobilised would depend on the seriousness of a particular incident, with rosters to be drawn up in advance to ensure enough staff are available.

Yeung also said officials were still discussing a revision of the code of conduct for civil servants, another measure announced by Chief Executive John Lee in his policy speech to strengthen civil service management.

Yeung said the code was set up in 2009 when the situation in society was different from now. She said people back then could not imagine that incidents happening in the SAR would threaten national security.

Asked on the radio programme whether the term "impartiality" would appear, Yeung said the exact wording was still under discussion, but authorities would consult civil servants in the first quarter of next year with a draft of the updated code of conduct.

The minister had told lawmakers on Tuesday that the update would remove the term "political neutrality", so civil servants would not be able to use it as an excuse to avoid tasks, though they would still be expected to act impartially.

She hoped the final version of the code would be released in the first half of next year.