Teacher absences due to Covid are at their highest level since the start of the current school session.

The Herald has also learned a call-out aimed at encouraging retired and other lapsed staff to return to classrooms persuaded only 20 to re-register.

Union leaders said current shortages were generating “enormous” pressure as schools battle to stay open amid the Omicron variant’s rapid spread.

Government statistics show 2,936 teaching staff were absent for Covid-related reasons on January 11 - up from 2,048 on December 14.

There were also 99,141 coronavirus-linked pupil absences on December 21 - an increase from just over 50,000 on December 17. The surge was driven largely by self-isolation requirements and because parents decided to keep youngsters away.

Although few establishments have had to close or bring in remote learning since the start of term, efforts to ensure pupils can continue to attend have created significant strain.

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There are reports that large numbers have been herded into areas such as canteens or halls. Teachers are also being pulled away from normal duties to look after children or provide general supply cover.

Meanwhile, the General Teaching Council for Scotland (GTCS) has confirmed only a tiny percentage of lapsed teachers who were contacted about returning to schools opted to sign up. It comes after Education Secretary Shirley-Anne Somerville told MSPs that a call-out had been issued in a bid to boost capacity during the pandemic.

GTCS bosses said an email was sent on September 10, 2020, to 2,051 lapsed registrants, which included those no longer teaching for reasons other than retirement. Following this, 56 registration packs were issued, with 20 individuals completing the process and returning to register. The majority where notionally of retirement age.

Ms Somerville told MSPs on Wednesday: “Earlier on in the pandemic, we did, of course, put a call out via the General Teaching Council for Scotland for retired teachers if they wanted to come back into the profession for some time.

“The uptake of that, I have to say, was exceptionally low. A very small, small number came forward from that.”

HeraldScotland: Education Secretary Shirley-Anne Somerville said a call-out had been issued to attract lapsed teachers.Education Secretary Shirley-Anne Somerville said a call-out had been issued to attract lapsed teachers.

Efforts to attract lapsed teachers come amid reports that the availability of supply staff is exceptionally poor.

Despite the call-out’s lack of success, Ms Somerville indicated ministers had not given up on the idea of reaching out to individuals who have dropped their registration. “It is something that we are looking to do again,” she said.

Larry Flanagan, general secretary at the EIS union, said: “The latest data reveals a record level of teacher absence from Covid infection and also from Covid-related factors.

“Despite this, schools have largely stayed open in the first week back as teachers at all levels, as well as other school staff, have really gone the extra mile to ensure that in-person teaching and leaning has been maintained. 

“This is creating enormous pressure on staff, however, and, as the recent EIS survey on workload revealed, the health and wellbeing of teachers is being hugely compromised.

“We are not in a business as normal scenario and councils and the Scottish Government need to ensure that the sole focus is on supporting teaching and learning and all the other drivers of excessive workload are set aside.”

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A Government spokeswoman said: “Our guidance for schools includes advice on workforce planning and support to deal with the impacts of Covid-19.

"Partners in the Scottish Negotiating Committee for Teachers have previously agreed a number of contingencies for flexible staff resourcing in order to maintain continuity in education, such as the ability, if necessary, to combine classes in stages, to increase class contact time or to relocate staff temporarily. 

“Our funding for additional teachers has already resulted in there being more than 2,000 extra teachers in our schools than was the case before the start of the pandemic.”