The islands have never been part of the European Union, and thus were not a party to the 2016 referendum on the EU membership, but were part of the Customs Territory of the European Community by virtue of Protocol Three to the Treaty on European Union. In September 2010, a Channel Islands Brussels Office was set up jointly by the two Bailiwicks to develop the Channel Islands' influence with the EU, to advise the Channel Islands' governments on European matters, and to promote economic links with the EU.