Two babysitters who raped a 12-week-old baby are to have their jail sentences reviewed by the Lord Chief Justice.
Alan Webster, 40, and his girlfriend Tanya French, 19, both from Hatfield in Hertfordshire, pleaded guilty to rape.
In January, Webster was given a life sentence, with a six-year minimum, and French was jailed for five years.
Three Court of Appeal judges decided on Monday that an appeal to increase their sentences should be presided over by Lord Philips.
The appeal was launched by the Attorney General Lord Goldsmith QC, who asked the court to increase the jail terms he branded "unduly lenient".
At the start of the proceedings in London Lord Justice Rose, sitting with Justice Penry-Davey and Mr Justice Fulford, announced: "We take the view that this case ought to be considered by a constitution in which the Lord Chief Justice presides."
Lord Justice Rose said the appeal raised "fundamental" questions in relation to double jeopardy - when a defendant faces sentencing twice - and in relation to discounts for pleas of guilty.
Webster was jailed for life after pleading guilty to rape, indecent assault, permitting indecent images to be taken of a child and making indecent images - he was told he must serve a minimum of six years before being considered for parole.
French, 19, was jailed for five years and given an extended licence period of five years after admitting the same charges.
Webster and French raped the baby girl and took photographs of the abuse.
The baby's mother criticised the sentences given to the pair as a "joke", and said they should serve at least 25 years for their sickening attacks.