An Irishman who is married to a Colombian national and who lives in Spain should be allowed to bring his wife to the UK without having to apply for a UK travel permit every six months, according to a legal opinion issued by the European Court of Justice.

Under British law, Helena Patricia McCarthy, originally from Colombia, has had to apply for a special entry permit every six months any time she accompanies her husband, Sean Ambrose McCarthy, to the UK, where the couple have property.

The court heard that Mr McCarthy, who has joint British and Irish citizenship, would travel regularly from the couple's home in Spain to the UK for heart treatment.

The opinion, issued by one of the court's advocate generals, could have major implications for British immigration rules if it is confirmed by a judgment of the full court.

Under British law non-EU family members of EU nationals must be in possession of a "family permit" if they wish to visit the UK.

The permit is necessary, according to the UK authorities, to avoid identity fraud and sham marriages.

The permit is valid for six months and can only be renewed in person at a UK embassy.

In Mrs McCarthy's case this meant an 11-hour round trip by car from Marbella to Madrid in order to renew the UK entry permit.

On each occasion she would have to fill in details of her finances and employment situation.

The McCarthys took action against the UK government under the EU's freedom of movement rules.

The British High Court then referred the case to the European Court of Justice in Luxembourg.

In this morning's opinion, the court heard that EU freedom of movement rules should apply to EU citizens and third country family members, such as Mrs McCarthy, when they were making short trips to other member states where the citizens concerned, in this case Mr McCarthy, were nationals.

The advocate general in the case pointed out that the couple had not been accused of ever previously abusing the family permit system and as such they had been deprived of their rights under freedom of movement rules.

The advocate general also held that the requirement for a "family permit" renewable every six months was tantamount to needing a visa, and that was against the spirit and substance of the EU's freedom of movement rules.

The fact that the UK disregarded Mrs McCarthy's Spanish residence permit was contrary to the EU principle of mutual recognition.

The UK authorities should have recognised Mrs McCarthy's Spanish permit unless they were "seriously shaken" by "concrete" evidence that she had abused the system, the court heard.

Otherwise, the advocate general added, the UK authorities would be able to simply circumvent freedom of movement rules.

The full judgment is expected in a number of months.

In 80% of cases an advocate general's opinion is confirmed in the full judgment.