A coronavirus outbreak among staff has closed a primary school, days after unions reported the trust which runs it to the Health and Safety Executive (HSE).
Cedar Primary School in Northampton, which had partly reopened on Monday, closed on Wednesday after two support staff tested positive for the virus.
Two unions reported the David Ross Education Trust (DRET) over concerns with its Covid reporting procedure.
DRET has been approached for comment.
Unison and the GMB's complaint against the trust, which was founded by Carphone Warehouse boss David Ross, came before the Cedar Primary outbreak was known.
All of its 25 staff have now been tested for Covid-19.
Rachelle Wilkins from the GMB told the Local Democracy Reporting Service she had "real concerns" that the cases in schools could lead to a community outbreak of the disease.
"There have been four cases now at DRET schools across three schools." she said.
"We have asked DRET 'what are you going to do about it' and they just keep throwing government guidelines at us."
Cedar Primary was the second of the academy chain's schools in Northampton forced to close by the pandemic, following the partial closure of Malcolm Arnold secondary in mid-March.
There has also been a case at Briar Hill Primary School in the town.
Northamptonshire County Council said it was "aware" of the situation.
Schools nationwide reopened to selected year groups this week after being closed to most pupils since March.
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