(a) The material validity of an international arbitration agreement must be determined in accordance with the law chosen by the parties to this agreement or, without specifying, according to the applicable law at the place (seat) of the arbitration procedure. This is a difficult issue and will depend on the circumstances of the case and the approach of the arbitral tribunal or the national court dealing with this issue. This lack of clarity can lead to costly satellite proceedings that would not be necessary if the law governing the arbitration agreement were defined in the arbitration agreement. (b) the formal validity of an international arbitration agreement must be determined according to the formal rules of validity of the right of arbitration of the country in which the arbitration is based. Although the Supreme Court considered that there may be circumstances in which english courts would decide to defer a foreign jurisdiction to a foreign jurisdiction because of the scope of a compromise clause, in practice it would be very little.17 In particular, the Court confirmed that it would generally be inappropriate: a foreign court in circumstances in which the foreign judicial procedure that determines the scope of arbitration is the same procedure which is the subject of the anti-appeal decision sought.18 It is also unclear whether and how the doubts expressed in this case as to the approach to tacit election in Sulamerica will influence the role and relevance of seat law in determining the law of the arbitration agreement in England. In particular, this recent judgment did not give priority to the approach of the Court of Appeal previously in C/D, which prioritized the right of the seat as the most closely related and real system of law with arbitration, over the applicable law of the main contract. Level 3 With which legal system does the arbitration agreement have its closest and most real relationship? ”The starting point of the Common Law … is that the parties are free to choose the legal system that will govern their contract, unless their election is contrary to public policy. These legal systems may be elected (explicitly or implicitly) by the parties. They may also differ. For example, the parties may decide that their material rights and obligations arising from a construction contract are governed by French law, but that any subsequent arbitration proceedings have their headquarters in London, with the arbitrators adopting English legal procedures and their arbitration agreement in accordance with English law. This may be desirable, for example, to seek a ”neutral” forum in the country of origin of one of the parties, or if one or both parties have concerns about the independence of national courts.