The former rock singer was handed a 35 year sentence at Cardiff Crown Court last year after admitting 13 sex offences.
Among them included the attempted rape of a baby.
After a judge branded the disgraced star a dangerous sexual predator, Watkins was handed a 29 year prison term followed by an additional six years on licence.
However, the now grey-haired vocalist - who said his child sex offences were "megalolz" - has complained his sentence was too harsh.
Watkins, now 37, will appear in front of a panel of judges next week - and will decide whether his case can go any further.
Application for permission for an appeal hearing was first lodged with the court in January - just a few weeks after his conviction.
Originally Watkins had pleaded his innocence to a string of offences - despite a damning video of him engaging in sexual activity with an 11-month old baby.
However, he changed his plea at the last minute - averting a trial - but then complained he had not realised that a guilty plea had made him "look guilty".
A court heard that after sexually touching a groupie's baby, Watkins tried to have penetrative sex with the child.
He also encouraged a second fan to abuse her child during a webcam chat and secretly stashed child porn videos, some of which he had made himself.
Trial judge Mr Justice Royce told Watkins: "Those who have appeared in these courts over many years see a large number of horrific cases.
"This case, however, breaks new ground. I am satisfied that you are a deeply corrupting influence, you are highly manipulative, you are a sexual predator, you are dangerous.
"The public and, in particular, young females need protection from you."
Watkins' two accomplices, Woman A and Woman B, were jailed for 14 years and 16 years respectively.
Earlier this month, former Lostprophets guitarist Lee Gaze said he smashed one of his platinum record discs to pieces in anger at Watkins' sick exploits.
He said: "I don't know how his badness can't cancel out our music. We had platinum records in our houses. I smashed the Liberation Transmission one the other day."
Watkins' appeal hearing is to be heard at Cardiff Crown Court on Wednesday, July 23.