The union's comment comes after teachers complained that their schools asked all or half of the teachers and staff to work on campus during the fifth wave.

The Hong Kong Education Workers Union said it has received numerous such complaints from teachers across different schools.

The union said such a move by schools does not take into consideration the health and safety of teachers and their families.

It called on the Education Bureau to establish clear guidelines and to restrict the number of staffers working on campus to one-seventh of all staffers of the school for as long as face-to-face classes are suspended.

Schools have been asked to keep their campuses open during the face-to-face class suspension to take care of students who have to go back to schools due to a lack of carers at home. Schools are also to arrange staff to be on duty but authorities have not put a limit on the number of staff permitted on campus.

Chairman of the union Wong Kin-ho said the epidemic transmission is serious and dozens of staffers gathering in schools can pose a serious threat to their health.

"Frontline teachers have rich experience in online teaching as the that has been the new norm of teaching for the last two years, so it is unnecessary for schools to ask teachers to conduct online teaching on campus," Wong said.

Education sector lawmaker Chu Kwok-keung also agreed with the union and said teachers could work at home, as crowds gathering on school campuses could disrupt anti-pandemic efforts.

Meanwhile, the Hong Kong Federation of Education Workers also urged the government to provide guidance and support to schools on vaccine passports, which go into effect February 24.

It also called on authorities to announce the arrangements for the Hong Kong Diploma of Secondary Education examinations as soon as possible.