The law that marital rape was an offence, was not to be treated as retrospective despite being a common law change. The Court rejected complaints by two applicants who had been found guilty of raping their wives which was an undoubted extension of the concept of rape as had been previously understood.
Held: ‘It is however compatible with the requirements of Article 7(1) for the existing elements of an offence to be clarified or adapted to new circumstances or developments in society in so far as this can reasonably be brought under the original concept of the offence. The constituent elements of an offence may not however be essentially changed to the detriment of an accused and any progressive development by way of interpretation must be reasonably foreseeable to him with the assistance of appropriate legal advice if necessary.’ and ‘However clearly drafted a legal provision may be, in any system of law, including criminal law, there is an inevitable element of judicial interpretation. There will always be a need for elucidation of doubtful points and for adaptation to changing circumstances. Indeed, in the United Kingdom, as in the other Convention States, the progressive development of the criminal law through judicial lawmaking is a well-entrenched and necessary part of legal tradition. Article 7 of the Convention cannot be read as outlawing the gradual clarification of the rules of criminal liability through judicial interpretation from case to case, provided that the resulting development is consistent with the essence of the offence and could reasonably be foreseen.’ and the decision of the House of Lords withdrawing the husband’s immunity was no more than continuing ‘a perceptible line of case law development’ which had ‘reached a stage where judicial recognition of the absence of immunity had become a reasonably foreseeable development of the law.’