This disenfranchisement applied by the United Kingdom was successfully challenged before the European Court of Human Rights in 1999.

As a result, from 2004 Gibraltar was included by the United Kingdom within the South West England region for electoral purposes.

Spain took a complaint about Gibraltar participating in EU elections to the Court of Justice of the European Union, objecting to the enfranchisement of Commonwealth citizens and the creation of a combined electoral region, but its case was unsuccessful.

This was in large part due to the perception that the Labour Government in Britain had "betrayed" Gibraltar by attempting to negotiate a constitutional settlement involving joint sovereignty with Spain.

The Conservatives were perceived as being unequivocal in their support for Gibraltar's continued British status.