Some homosexual acts involving older men and boys aged under 17 that were illegal up to last week have been decriminalised by the Government's rushed legislation.
Up to now, the law meant that men could be prosecuted for engaging in grossly indecent acts with 15/17-year-old boys, even if the boy had given his consent to the acts.
However, the legislation rushed through the Oireachtas by Minister for Justice, Equality and Law Reform Michael McDowell offers more limited protections.
The legislation, needed to close loopholes created by the Supreme Court's judgment, covers all forms of penetrative sex, including intercourseand oral sex.
The Department of Justice, Equality and Law Reform said last night that "mild acts" such as "heavy petting" between young males or, it conceded, between a young male and an older one would not be covered by the legislation.
"It is not clear that they could ever be prosecuted, if there was consent.
"If there wasn't consent it would be regarded as sexual assault and it could be prosecuted," said an official.
Piloting laws through the Oireachtas that decriminalised homosexuality in 1993, the then minister for justice Máire Geoghegan Quinn said she would not abolish gross indecency laws because this would leave 15/17-year-old boys with "no protection against the commission of homosexual acts involving them", such as hand masturbation.
But the Department of Justice said yesterday that young gay males "are entitled to the same type of protections as a boy and a girl", adding that the Ombudsman for Children had pushed for legislation that would treat all equally.
The legislation as passed, however, distinguishes between girls and boys because boys can be prosecuted for having sexual intercourse under 17, while a girl cannot.
The Labour Party asked last night if Mr McDowell's Cabinet colleagues had understood that the legislation would "decriminalise certain sexual acts with boys that have been criminal throughout the history of the State?"
In the Dáil on Friday, Brendan Howlin warned that the legislation decriminalised acts that were up to then illegal. The Labour Tand the Minister repeatedly and sharply disagreed.
The schedule to the Criminal Law (Sexual Offences) Bill 2006, which was signed into law by President Mary McAleese on Friday night, repeals Section 4 of the Criminal Law (Sexual Offences) Act 1993.
Mr Howlin declared: "For example, if a 60-year-old sexually interferes with a consenting 15-year-old boy but does not perform penetrative sex, he is guilty of an offence of gross indecency under section 4 of the Criminal Law (Sexual Offences) Act 1993.
"However, the section is being repealed without replacement."
Rejecting his argument, the Minister for Justice said such behaviour was open to prosecution: "It is a sexual assault carrying a sentence of 14 years in prison.
"The deputy should check the law."
Shortly afterwards, he was even more specific: "For a 60-year-old man to engage in that act with a boy is a sexual assault carrying a sentence of 14 years in prison."
Last night the Labour Party said the situation might be even worse.
It could mean that "figures of authority", such as parents or guardians, could not be prosecuted for non-penetrative sexual acts on 15/17-year-olds.
The legislation imposes heavy penalties on any adult in a position of power over a child, such as a youth club leader, who has sexual intercourse or any other form of penetrative sex with a child.
