Fine Gael has strongly opposed a key finding of an Oireachtas child protection inquiry, which has recommended that the age of sexual consent be cut from 17 to 16 years.
The all-party Committee on Child Protection, chaired by Fianna Fáil TD Peter Power, also recommends that a constitutional referendum be held to stop adults claiming they did not know the age of a person under 16 with whom they had sex.
People in authority over children, such as teachers and scout leaders, should face life imprisonment if they have sex with one of their charges aged under 18, the committee also says.
Cutting the age of consent by a year was difficult, Mr Power acknowledged, though research indicated that most people believed 16 was already the legally permissible threshold.
Calling for a "very vigorous" sex education programme, Labour TD Brendan Howlin emphasised "that the age of consent is not the age of acceptability. It is whether or not it is criminal". However, Fine Gael leader Enda Kenny, speaking in Cork last night, said a reduced age of consent would send "a wrong signal to our children about values and standards.
"This decision is out of touch with the values and aspirations of the vast majority of parents in Ireland," he said. "Parents who want to live up to their responsibilities to nurture and protect their children."
Fine Gael Cork South West TD, Jim O'Keeffe, who represented the party on the committee, said he "wasn't convinced by the case made" for the new 16-year threshold.
Mr Power said the Supreme Court ruling in May that a man should be allowed to argue he did not know that a girl with whom he had sex was only 13 "had undermined the child protection system that had worked for 70 years and that had not given rise to a miscarriage of justice for 70 years". Minister for Justice, Equality and Law Reform Michael McDowell and the Minister of State for Children, Brian Lenihan, were ex-officio members of the committee, which began work after the summer.
Cautioning against the prospect of a speedy referendum, Mr McDowell said he would bring the committee's conclusions to the Cabinet as a matter of priority.
The committee also recommends that people found guilty of raping or attempting to rape a child under 16 should face a maximum sentence of life imprisonment, while first offenders should get no automatic reduction in sentence.
Mandatory sentences should not be introduced, it says, though they could be considered for authority figures found to have abused their relationship with under-18s.
Vetting rules should be tightened so that full details about an individual's past - including if they had been charged but not convicted of sex abuse offences - can be gathered and passed on to schools before they recruit staff.