Military and politician. He was expelled from the army after the Liberal Triennium because he positioned himself against the Cent Mil fills de Sant Lluís (Hundred Thousand Sons of St. Louis). He was readmitted to the army and fought against the Carlistas. 

Contreras took a stand against the Espartero regency in 1841 and in 1866, he joined General Prim in the failed insurrection in Madrid. He was deputy to the Constituent Assembly in 1869 and re-elected in Murcia in 1871. He participated in the assembly of the Democratic Federal Republican Party in 1872 in Madrid, before the Spanish general elections in April that year. He was an intransigent Federal Republican and was part of the party’s National Directory. During the First Spanish Republic, he was captain general of Catalonia (between February and March 1873). He went into exile in Oran (Algeria) and was amnestied in 1879. He lived for the rest of his life in Algeria.