[1] He is the son of the Aprista union leader, Luis Negreiros Vega and Juana Criado Morales.

His father was riddled with bullets by agents of the political police, in the middle of a public street during the dictatorship of General Manuel A. Odría on March 23, 1950.

After Victor Raul Haya de la Torre died, Negreiros was one of the natural leaders of the Peruvian Aprista Party but when the 1985 general election began, Alan Garcia was named as the candidate of the Peruvian Aprista Party, Negreiros moved away but eventually returned.

In the 1978 Constituent Assembly, he was elected as a member of Peruvian Aprista Party, standing alongside Victor Raul Haya de la Torre.

In 2001, he was elected Member of the Congress of the Republic of Peru, returning after a nine-year absence, representing Callao, and was reelected in 2006, serving until 2011, when he unsuccessfully ran for re-election due to a low number of votes and subsequently retired from politics.