The most significant development concerning foreign policy in the Lisbon Treaty is the creation of the post of High Representative of the Union for Foreign Affairs and Security Policy. This position will replace the High Representative for the Common Foreign and Security Policy (currently Javier Solana) as well as the Commissioner responsible for External Relations (Benita Ferrero Waldner).

Article 9e of the Lisbon Treaty states that:

"The European Council, acting by a qualified majority, with the agreement of the President of the Commission, shall appoint the High Representative of the Union for Foreign Affairs and Security Policy. The European Council may end his or her term of office by the same procedure (...) The High Representative shall conduct the Union's common foreign and security policy. He or she shall contribute by his or her proposals to the development of that policy, which he or she shall carry out as mandated by the Council. The same shall apply to the common security and defense policy."

As the Commission's President and other members of the Commission, the High Representative of the Union for Foreign Affairs and Security Policy will be subject as a body to a vote of consent by the European Parliament (Article 9). The High Representative of the Union for Foreign Affairs and Security Policy will have a double mandate: he or she will be both Vice President of the European Commission and Chairperson of the Foreign Affairs Council.

This would effectively be an EU Foreign Minister, with the role of representing the EU abroad in matters relating to the Common Foreign and Security Policy. The High Representative would also act as the Vice-President of the Commission, and would therefore be responsible for co-ordinating the competences that fall under the remit of the Commission, including: development, trade, economic cooperation, and humanitarian aid.

Despite the creation of this post, the EU still does not have its own diplomatic service and lacks appropriate foreign representatives and co-ordination between the external services of the Member States and the EU institutions. In order to improve this situation, the Lisbon Treaty foresees the establishment of a European External Action Service.