Headteachers are being relied upon to be part of the national test and trace system for Covid-19 and face being called on in the holidays, a union official has warned.
James Bowen, the NAHT's director of policy, said he feared school leaders could end up being on call for 365 days a year because they had "inadvertently" become part of the country's system for isolating cases of the coronavirus.
He said that it was school leaders rather than health agencies who were expected to identify and call any close contacts of a Covid case in schools, and he warned that there have been no alternative arrangements in place for this half-term holiday.
"Something that is really concerning me – and it's only in the past few weeks that I have appreciated that it is happening – is that basically headteachers have been asked to form part of the national test and trace and isolate infrastructure," he said.
“When you get a positive case in your school, you phone and hopefully get advice from either the Department for Education helpline or your regional public health team, but it's then down to the headteacher to phone all of the families in that bubble and tell them to self-isolate.
Coronavirus: The responsibility for tracking cases in schools
“So effectively heads are doing the work that really we thought the test and tracers would do.
"There are some real problems there. One is the amount of work that takes but the other thing is that we asking heads to do a job that they are just not qualified to do."
The DfE feels that heads, their deputies or teachers are best placed to get in touch with families because they know best who pupils' close contacts have been. It also notes that only students over 16 can download the test and trace app.
But Mr Bowen said this meant that school leaders had been left fielding questions on public health from dozens of parents, and he highlighted how in some cases "bubbles" of entire year groups were being stood down.
He added: "I think the fact that heads have been inadvertently brought into the test and tracing structure and have to make the calls to families themselves is something I don’t think anyone really appreciated back in September.
“I think we expected that a school would provide a list of pupils and contacts, and public health would phone the families. But actually what has happened is that schools are being told, ‘You need to tell all the pupils in that bubble to self-isolate rather than the test and trace people.'
“The other thing that worries me is that it is half-term and there are no other alternative arrangements in place.
“So if this week a child comes down with Covid and tests positive, at the moment when that gets flagged, authorities are expecting school leaders to still be receiving that call, identifying contact and making those phone calls in half-term now.
"But at the moment that would mean we are looking at headteachers potentially being on call 365 days a year.
"What is going to happen at Christmas time? Are we seriously saying that headteachers should be sat there on Christmas morning? That is not sustainable.
“It means you have constantly got to be ready to be phoning around groups of parents and that could happen at 4pm, 5pm 6pm in an evening, and that is a huge demand on top of everything else you have got going on in your school day.
“How long do you think it would take to phone and explain to every child in a bubble – say there is 30 in a class. It’s a pretty significant undertaking."
Mr Bowen said he was not aware of any other sector where the organisation itself was expected to carry out the tracking and tracing of Covid contacts.
Concerns that too much pressure is being put on schools to support track and trace have also been raised by a member of the Independent SAGE group of scientists.
At a briefing on schools on Friday, Dr Zubaida Haque said: "It is not fair that responsibility of which children, and how many children, should be going home should be left to schools, headteachers or to teachers. They are not the find, test, trace and isolate system here.
"We have a privately led test and trace system. The whole point of that system is that it is supposed to support institutions like schools."
Mr Bowen said managing who to send home in the event of a positive coronavirus case was also an enormous challenge for schools
"School leaders are expected to be able to tell the testers and the track and trace people all the people who a school pupil has come into close contact with," he said.
"In secondary school where you have pupils moving around from different lessons and different subjects, keeping track of all those different contacts and keeping on top of all of that is really challenging.
“I think at the beginning there was an assumption we all made that it would be quite simple. Someone gets a positive test and the bubbles goes off, which would be quite straightforward.
"I think what has emerged is that there has been a slight shift in emphasis: someone tests positive, only those in the bubble who have had close contact need to go off, and that provides quite a challenge for schools in terms of keeping on top of all of those contacts and who they would be."
A Department for Education spokesperson said: “Schools have measures in place to track pupils and manage bubbles so they can quickly identify close contacts if they need to.
“As set out in our guidance, if there is a confirmed case, schools must only send home those who have been in close contact to self-isolate. To reduce the burden on schools, we have provided all schools with a template letter to send to parents.”