The Attorney General, Sir Nicholas Lyell, described the two years' probation given to Karl Gambrill, 21, from Southampton, as 'unduly lenient'. At his trial at Winchester Crown Court last month, Judge Starforth Hill QC provoked outrage by describing the man's victim as 'not entirely an angel'.
Gambrill later confessed that he had fully expected to be jailed after he admitted attempting to have intercourse with the girl while he was babysitting her three years ago.
Judge Starforth Hill, 71, said he based his decision not to jail Gambrill on social reports which suggested that the girl was sexually experienced, having been involved in a children's 'sex gang'.
He took into account the fact that her abuser was 'inexperienced and immature'.
The girl's mother said after the case that the 'so-called sex gang' was simply a game of
doctors and nurses played when her daughter was about six.
'That was a perfectly natural thing and we have all done it,' she said.
She also said that her daughter, now aged 12, who cannot be named for legal reasons, was 'cracking up' as a result of the case.
'She was eight at the time and what does a little girl of eight really know about anything?' the mother said.
The sentence and the judge's comments led to calls for the vetting of all judges involved in trying sex cases.
Judge Starforth Hill, who has been criticised for his handling of sex cases in the past, refused to comment on the controversy his remarks provoked.
In a statement, a spokesman for Sir Nicholas said:
'The Attorney General has considered the case of Karl Gambrill and has concluded that the sentence was in his opinion unduly lenient and has applied to the Court of Appeal for leave to refer.
'This is an exercise of his power under Section 36 of the Criminal Justice Act, 1988.'