The issue focused on in the series of court cases was the power of the European Court of Justice  to stop the UK from leaving the EU.The court's decision in May to block a deal on the UK's continued membership of the EU was seen as a major victory for the campaign to stay in.The court was set up to deal with issues that would have an impact on the UK's membership of the EU.The issue is also under debate in the High Court.The court's decision in May to block