A teenager charged with engaging in sexual acts with a 14-year-old girl when he was 15, has lost a challenge to the constitutionality of a law preventing him from advancing a “Romeo and Juliet” consent defence.

His criminal trial will proceed at a later date.

The Criminal Law (Sexual Offences) Act 2006 provides, when a person is charged with engaging in sexual acts with a child aged under 17, the so-called peer consent, or “Romeo and Juliet” defence, is only available if the child was then aged 15 to 17 and the accused was younger, or less than two years older, than the complainant.

The accused claimed he made a reasonable mistake that the girl was aged 15 on two dates in 2023 when he allegedly engaged in sexual acts with her, an offence known as defilement.

The girl was three months short of her 15th birthday at the time and the accused was seven months older.

In High Court judicial review proceedings, the accused, now aged 18, argued the law preventing him from availing of the peer consent defence in a situation, where he made a “reasonable mistake” about the complainant’s age, was unconstitutional.

The non-availability of that defence where a complainant is under 15 breached the article 40.1 constitutional guarantee of equality before the law, his lawyers argued.

In a recently published judgment, Judge Garrett Simons said the legislature has determined that for a child to have capacity to give a legally effective consent, they must be aged at least 15.

He disagreed that the failure to extend the peer consent defence to a person who made a reasonable mistake that a child was aged 15 renders the relevant provision, section 3.8 of the 2006 Act, invalid.

This constitutional challenge was “tightly framed” in that it focused on the absence from the peer consent defence of any allowance for a reasonable mistake as to age, he said.

There was no challenge, he noted, to the threshold of 15 years “as a proxy for maturity and capacity”.

The use of an age threshold as a proxy for the capacity to give informed consent to sexual activity is “rationally connected” to the legitimate legislative purpose of the 2006 Act, he held.

It reflects the “self-evident” principle that adults and children differ in maturity and is consistent with well-established case law allowing for the use of an age threshold as a proxy for maturity.

The failure to make any accommodation, as part of the peer consent defence, for the contingency of a reasonable mistake as to age, did not breach the constitutional guarantee of equality before the law, he held.

The judge noted another argument advanced on behalf of the accused was rejected last year by the Court of Appeal in a separate case. That contended, in circumstances of reasonable belief the complainant was aged 15, the accused lacked the necessary intent to justify a criminal conviction.

For reasons including the public interest in clarifying whether the equality guarantee applies, his provisional view was that no order for costs should be made in favour of the State respondents and the Legal Aid (Custody Issues Scheme) should apply in relation to the applicant’s costs.

His decision, he stressed, only concerns the constitutional issue, does not deal with the merits of the underlying criminal prosecution and the accused has the presumption of innocence which can only be displaced following a criminal trial in due course of law.