THE High Court has heard an elderly man should not stand trial for rape because it was legal, almost 50 years ago, to force his wife to have sex.

The man, now 80, has been charged with offences including two counts of rape against his wife in 1963.

Yesterday the Full Court of the High Court, sitting in Adelaide, was asked to intervene and prevent his trial from going ahead.

David Bennett, QC, for the man, said 1960s attitudes made Australia a "socially backward country" and contemporary values should not be applied to the case.

"In 1963, Australia was a very unenlightened and socially backward country by modern standards," he said.

"In major respects, 1963 was a pre-enlightenment year and 1991 was a post-enlightenment year."

Mr Bennett said reinterpretations of law should not criminalise "conduct which previously was not criminal".

"This court should ... make it clear that no common law rule ... can have the effect of criminal conduct which was not criminal at the time."

The man and his wife were married from 1962 to 1971, when common law held a husband could not rape his wife because the marriage "contract" granted him an unfettered right to sex.

In 1991, the High Court ruled marriage did not mean a wife gave "irrevocable consent to sexual intercourse by her husband".

Yesterday, South Australian Solicitor-General Martin Hinton, QC, said the man should be tried. In written submissions he said marital exemption was, by 1963, no longer part of common law.

"Even if it was (the case) at the time (the law) was written, it was no longer part of the common law of Australia by 1963."

Mr Hinton asked the court to dismiss the man's appeal and allow the trial to proceed.

Previously the Court of Criminal Appeal said the prosecution could continue because rape in marriage was a crime regardless of the law at the time it occurred.

"Since then (1963) it has become clear that it is no longer the law that a husband cannot be guilty of raping his wife," Chief Justice John Doyle said. Dissenting, Justice Tom Gray said the defendant should be tried based on the laws of the day while Justice Richard White agreed with Chief Justice Doyle.

The hearing continues.

Originally published as Rape in marriage 'not criminal'