But Secretary for Education Kevin Yeung Yun-hung said there are no grounds to support the claim that the teachers are leaving because of Hong Kong's Covid-19 policies.

The Education Bureau has implemented, since 1998, the Native-speaking English Teacher Scheme in public-sector primary and secondary schools to provide one native-speaking English teacher post for each school that meets the relevant criteria.

Yeung said the respective rates of attrition of native-speaking English teachers in primary and secondary schools last year were 11 percent and 13 percent.

The attrition rate in secondary schools reached the highest in the past five years, also an increase of four percentage points from 9 percent in 2019/20.

Yeung said, as seen from the statistics for five years, the rates of retention and attrition of native-speaking English teachers have been largely stable, and there was no imbalance of demand and supply at this stage.

He said the reasons for those teachers to leave their service various, including retirement, family reunion, and they wish to work or live in other countries: "The decision of the teachers to take up teaching posts in Hong Kong or not depends on their personal considerations."

"There are no substantive grounds for attributing the departure of native-speaking English teachers or their decision to or not to come to teach in Hong Kong to our compulsory quarantine measure," he said.

He added that although the recruitment of native-speaking English teachers has been affected by the global pandemic in the past two years, Hong Kong still has a sufficient number of them to maintain a stable team.

The bureau expected schools could still recruit sufficient teachers to meet the demand in the 2022/23 school year.

He continued that the bureau would exercise discretion to allow native-speaking English teachers at retirement age to continue teaching and will enable the employment of temporary teachers to fill the vacancies.