The suspended sentence handed to a teacher for having sex with one of his pupils cannot be reviewed for being too lenient, the Attorney General confirmed.
Stuart Kerner, a former teacher at Bexleyheath Academy in south-east London, was found guilty of two counts of sexual activity with a child by a person in a position of trust after carrying out an 18-month affair with the 16-year-old girl.
The 44-year-old was handed an 18-month suspended sentence and walked free from court after a judge ruled that the teenage victim "groomed" him, and he was "emotionally vulnerable" as his wife had suffered a miscarriage.
During the trial at Inner London Crown Court, the jury heard Kerner took the virginity of the girl in an empty room at the school the same week his wife suffered a miscarriage.
The Attorney General said they would be reviewing whether the sentence handed down to Kerner was too lenient following a number of complaints. It only takes one person to file a complaint to trigger the process.
However, the Attorney General's Office has said it will not refer the sentence over to the Court of Appeal as it does not meet the criteria under the unduly lenient sentences scheme.
A spokesperson added: "After a number of complaints, we carefully considered whether Stuart Kerner's sentence could be referred to the Court of Appeal for being too low - as part of the unduly lenient sentence scheme.
"Mr Kerner's crimes are not included in this scheme, meaning the law officers are unable to refer this. However, it's important that the public can challenge what they believe to be exceptionally low sentences. We have been looking at whether the scope of the current scheme is right."
Upon sentencing, Judge Joanna Greenberg QC told Kerner the girl was "obsessed" with him and saw no evidence he initiated the affair.
She said: "She pursued you. Her friends said she was stalking you. She hung around where she would be near you. She had been obsessed with you for a long time.
"If grooming is the right word to use, it was she who groomed you, [and] you gave in to temptation."
She added: "There is no evidence you encouraged her in any way. There is no evidence you groomed her. If anything it was she who groomed you. You gave way to temptation at a time when you were emotionally vulnerable because of problems with your wife's pregnancy."
The ruling was criticised by children's charities. Marilyn Hawes, a former teacher and founder of the charity Enough Abuse UK, told the BBC: "She was still a pupil and she had a right, as did the parents or her carer, to expect she would be secure and safe in those hours in school with someone who had been given that trust, and it was a total breach of trust.
"I just do not understand where the judge was coming from when she says she stalked him. He abused his position."
Jon Brown, from the NSPCC, added: "This was an abusive relationship and young people involved in situations like this can be damaged in many ways. Teachers have a duty of care to their pupils and Kerner should have taken steps to distance himself from the girl rather than encouraging her behaviour."
Kerner, of Aylesford in Kent, was found guilty of two counts of sexual activity with a child by a person in a position of trust. He was cleared of four counts of sexual activity with a child by a person in a position of trust, and cleared of two counts of sexual activity with a child, which reportedly relate to when the victim was 15.
He was made to sign the sex offenders' register as part of his sentence.