The Dublin Rape Crisis Centre has called for a definition of consent to be put into legislation following a ruling from the the Supreme Court today.

It finds that the prosecution will have to prove there was no consent for a man to be convicted of rape, after the Director of Public Prosecutions asked the court to clarify the law in cases where a man charged with rape claims the woman agreed to sex.

If it's proven that no consent was given, the jury will also have to consider the accused state of mind at the time.

Under section nine of the amended Criminal Law (Rape) Act 1990, consent is defined as "an offence that consists of or includes the doing of an act to a person without the consent of that person any failure or omission by that person to offer resistance to the act does not of itself constitute consent to the act."

Noeline Blackwell, CEO of the Dublin Rape Crisis Centre, said the law is still focusing on the accused and "not on the reality".

"The Supreme Court set out first of all that sexual intercourse without consent is rape", she said. "But the question that they really had to tease out a bit was the mental element of an accused when they're having that sexual intercourse.

"In Irish law, if a person is having sexual intercourse with a woman and he really believes he has her consent, that will be a defense of rape."

The topic of consent is being widely discusses on foot of author Louise O'Neill's RTÉ 2 documentary Asking For It.

"it's really useful that young people and older people are having conversations as to whether they are consenting to the sexual activity they are engaged in ... That will actually change our landscape around sexual violence in Ireland."