 As a UCD member, at the 1977 General Election, he was elected to the Spanish Congress of Deputies representing Valencia Province and was re-elected in the subsequent election in 1979.In 1978 Muñoz was chosen as one of the members of the Spanish delegation in the Council of Europe later becoming President of the Spanish delegation and Vice-President of the Council.He also worked as an advisor and promoter for the PRISA group, the largest publisher in Spain.