López-Istúriz White has been in Brussels since 1997, when he worked as an assistant to the People’s Party delegation at the European Parliament. He held this position until 1999, when he was called by then-President of the Spanish Government José María Aznar to become his personal advisor for almost four years. In 2002, he returned to Brussels upon his election as Secretary General of the European People’s Party. Two years later, he was elected MEP, holding the two positions up to April 2022. Since January 2008, López-Istúriz White has been Secretary Treasurer of the Wilfried Martens Centre for European Studies.

As an MEP, he is the Chairman of the Delegation for Relations with Israel. He sits on the Committee of Foreign Affairs and is a substitute on the Subcommittee on Security and Defence. López-Istúriz White is also a Member of the Delegation to the Parliamentary Assembly of the Union for the Mediterranean and the Delegation for relations with the Arab Peninsula as well as a substitute for the Delegation for Relations with the United States. In addition, he serves as President of the European Union-United Arab Emirates (UAE) Parliamentary Friendship Group and Vice-Chair of the European Parliament Intergroup on Children's Rights. In 2022, he was named Honorary Vice-Chair of the Conservative European Forum.