Article 22U.K.
Where related actions are brought in the courts of different Contracting States, any court other than the court first seised may, while the actions are pending at first instance, stay its proceedings.
A court other than the court first seised may also, on the application of one of the parties, decline jurisdiction if the law of that court permits the consolidation of related actions and the court first seised has jurisdiction over both actions.
For the purposes of this Article, actions are deemed to be related where they are so closely connected that it is expedient to hear and determine them together to avoid the risk of irreconcilable judgments resulting from separate proceedings.