The EU court has ruled UK and Gibraltar must be treated as a single EU member.
This comes after the European Court of Justice made a ruling on a tax dispute between the Gibraltar Betting and Gaming Association and the UK tax authorities.
They ruled that trade between the two was not the same as trade between separate EU member states given their history.
The court said its conclusion should not be understood as undermining the separate and distinct status of Gibraltar.
Such a decision could complicate the Rock’s hopes of being given a special status after Brexit.