The former head of Ofsted will return to teaching next month to help a school with high staff absences.

       Sir Michael Wilshaw, the former chief inspector of schools in England, will teach history to pupils in a south London school in January to help a headteacher who is expecting more absences in the new year.

       It comes after Nadhim Zahawi, the Education Secretary, has urged ex-teachers to sign up to help with Covid-19 staff shortages in the new year.

       But school leaders have warned that the initiative is unlikely to happen quickly enough to help schools when they return in January – especially as retired teachers could be put off by rising Covid-19 cases.

       Former head Sir Michael, who is over 70, said schools should be kept open “at all costs”, telling BBC Radio 4’s Today programme: “We’ve got to keep schools open whatever and if that means people like me going back into the classroom so be it.”

       Sir Michael, who temporarily returned to teach in a north London school during the first Covid-19 wave, told Sky News that members of his family had previously advised him not to go back into the classroom, but he was glad that he had and felt it is “a moral imperative”.

       The Government is pleading with recently retired teachers, or those who trained as teachers and changed career, to “find even a day a week for the spring term to help protect face-to-face education”.

       Mr Zahawi has said former teachers who are available to return should apply on the Get Into Teaching website and ideally start the process before Christmas Eve so they can join the workforce from January.

       Doubts over recruiting recently retired teachers

       Julie McCulloch, director of policy at the Association of School and College Leaders (ASCL), said: “It remains to be seen whether this initiative can attract ex-teachers in the kind of numbers to make any real difference, but we feel it is highly unlikely it will happen quickly enough to help schools when they return in the first week of January.

       “We also question whether ex-teachers will have much appetite for returning to classrooms given the high number of students who have tested positive in recent weeks.

       “They may have been more encouraged had the Government's responses to providing schools with high-quality ventilation equipment and to urging students to test at home not been so lacklustre.”