Schools need more powers to turn away pupils who are sent home because of Covid-19 symptoms but then are sent back prematurely.
The NASUWT teaching union says that it is increasingly concerned that this situation could put school staff and other pupils at risk of contracting Covid-19.
It is calling on the Department for Education to ensure schools can refuse to readmit a pupil who went off with Covid symptoms until either a 10-day isolation period has passed or proof of a negative coronavirus test can be provided.
The union says this needs to be backed up with updated DfE guidance provided to schools.
Government guidance states that: ”Schools should not request evidence of negative test results or other medical evidence before admitting children or welcoming them back after a period of self-isolation”.
NASUWT general secretary Patrick Roach said: “It is clear that some parents will struggle where their children are required to self-isolate, and indeed a lack of financial support for parents may well be a driver for pupils to be sent back to school inappropriately.
“But this cannot trump the requirements to self-isolate and if infectious children are sent back to school, this risks a much larger outbreak.
“Whilst the NASUWT agrees that a negative test is not required after the requisite period of self-isolation, this is different from a child returning early from a suspected case.”
He said that schools needed to be able to assure themselves that pupils returning to schools do not have Covid.
He added: “Where a child is sent home with Covid-19 symptoms they should be tested and the school should be able to ask for this result in order to ensure the health and safety of others in the school.
“Schools should be given the power to refuse to admit the child until the 10-day isolation period has elapsed or proof of a negative test result is provided. Taking it on trust that the child has tested negative is clearly insufficient.”
The DfE has been contacted for comment.