Rivera was elected president of Ciudadanos in 2006 and stepped down from the role in 2019 after the party lost a large proportion of its seats in the Spanish general election.
Before being elected as a representative in the Catalonia Parliament in 2006, Rivera was a lawyer for CaixaBank. He studied law in Universitat Autònoma de Barcelona and Esade Law School.
Martinez-Echevarria has around 120 professionals. The firm has 11 offices in Spain, as well as having offices in Portugal, Turkey, Bulgaria and Romania.
Its 2018 revenue stood at €17 million, up 8 per cent on the previous year.
Martinez-Echevarria Abogados was founded by Rafael Martínez-Echevarría in 1983.