Following his graduation Pérez joined his alma mater, University of Seville, as an adjunct professor.[2] He worked at the University of Valencia as an associate professor from 1972 to 1974.[2] He then joined the University of Seville and worked there until 1981.[2] He was elected to the Spanish Parliament representing the Communist Party of Spain in 1979, and his tenure at the parliament lasted until 1986.[2][3]
Pérez served at the European Parliament for four consecutive terms between 1987 and 2004. In the second term of the European Parliament he was a member of the Communist and Allies Group and in the third term he was a member of the European United Left.[4][5] He was elected from the United Left for both terms.[4][5] Pérez was one of the leaders carrying out a very successful election campaign in the 1989 European Parliament election for the United Left.[6] In the fourth and fifth terms at the European Parliament, he was part of the Party of European Socialists and elected to the Parliament from the Spanish Socialist Workers' Party.[1][7] He was the vice president of the European Parliament between 1989 and 1992.[2]
Pérez was a member of the Council of Taxpayers until 2012.[2] He is author of three books on tax laws.[2]
Personal life
Pérez is married and has two daughters.[2] He is a fan of bullfighting.[6]