The head of St Mary’s Catholic School in Bishop’s Stortford has left with immediate effect after just two-and-a-half years in the role. Tom Johnston took over as headteacher in September 2021 when his predecessor, Andrew Celano, was appointed chief executive officer of the St Francis of Assisi Catholic Academy Trust, a family of eight Catholic schools in the Roman Catholic deanery of the Lea Valley. In a letter to parents dated March 26, two days before the end of spring term, St Mary’s chair of governors Paul Carroll wrote: “I am writing to inform you that Mr Johnston has decided to leave his…