Portugal is in a political and economic union.
The European Union ( EU ) is a political and economic union of member states that are located primarily in Europe . Portugal . The Portugal -- Spain border is 1214 km long and considered the longest uninterrupted border within the European Union . A founding member of NATO and the Community of Portuguese Language Countries , it is also a member of numerous other international organizations , including the United Nations , the European Union , the eurozone , and the OECD .