Two sisters who were sexually abused by their stepfather over a 10 year period say they would like to see charges brought against their mother for not reporting the crime.

55-year-old John Joe Patterson from Tipperary was yesterday jailed for six and a half years for sexually abusing his step-daughters when they were both aged nine.

Vanessa and Emma Witherow say they feel 'overwhelmed and relieved' after the sentence was handed down.

Despite his admissions of guilt to gardaí, and his subsequent conviction at Nenagh Circuit Court, John Joe Patterson's wife Francis - who is also the girls' mother - has stood by her husband.

"There will never be closure there, she's still sticking by him", Emma told the Pat Kenny Show here on Newstalk.

"She's not entitled to the name 'mother' - you don't do that to your children", Vanessa said.

"She's going to be the lonely one now, she picked him over us and hope she regrets it".

On the abuse itself, Emma said: "At nine years of age I didn't know what was going on but as I got older I knew it was wrong. But I was so terrified of him - I still am".

"It wasn't till my later years that I told my mother, Vanessa told mammy when she was younger. It wasn't till I was 18 that I told mammy".

Emma says she took Vanessa with her when she left the home: "I wasn't leaving her there for her to be his next victim, even though I didn't know that she already had been".

The sisters stated they did not know they were both being abused until they were leaving the house.

"Looking back now I can't believe at 13 (years old) I was gone - you wouldn't see it today without anyone asking questions", Vanessa said.

Emma also recalls that her step-father called to her home after her child was born.

"He came to my home where I'm living now - the abuse didn't happen that day cause I held my son in my arms, and still to this day feel very guilty for doing so".

"It's like I used my own son to protect me - but the abuse didn't happen and that was the last time he came to my house".

On having their mother prosecuted for not acting on the abuse, Emma says they would like to see that happen.

"In my eyes she should (face the law) because a mother shouldn't do that to her kids".

Anyone affected by this story can call the Dublin Rape Crisis Centre on 1800-77-88-88