If Mr Edson, who has been suspended on full pay since he was charged, decides to go back to school next week, he will face a disciplinary inquiry into his conduct.
Even if he resigns before the inquiry, the governors will be legally obliged to send a report to the Secretary of State which could lead to him being placed on List 99, the teachers' blacklist.
Mr Edson also now risks being charged with perjury. Following revelations in a Sunday paper by the girl's mother that her daughter had suffered a miscarriage, police say they may reopen their investigation.
The Department for Education and Employment has recently introduced guidance which says relationships between teachers and pupils will be judged as inappropriate behaviour on the grounds of an abuse of trust.
Legislation making teacher-pupil relations illegal is expected to be passed in the next Parliamentary session - it provided the background for the recent controversy involving the chief inspector, Chris Woodhead, who has denied claims that he had an affair with a sixth- former when he was a teacher in the 1970s.
The story of Mr Edson and Rachel Russell was described in the Daily Mail, which paid them pound;40,000, as a sorry and sordid tale. The couple met at Wyke Manor school and started a relationship when Rachel was 15.
Mr Edson, 32, was cleared of the charges against him after Rachel gave evidence to the court via a video link insisting that they did not have sex.
Mr Edson, who was represented by the National Association of Schoolmasters Union of Women Teachers, went against the union's advice to sell his story to the Daily Mail.
The couple revealed that they started a relationship when she came to his house to babysit his daughter.
Mr Edson told the Mail: "I agree totally that teachers shouldn't have relationships with pupils, but I don't feel I have abused my position. She matured much faster through knowing an older man like me than she would have done without the relationship."
They said they planned to marry.