Álvarez was born in Dehesas (León) [es] in Ponferrada. He graduated with a law degree.[1]
Running for the People's Party (PP), he was elected to the city council in 1991 and was the leader of the opposition to Celso López Gavela [es], mayor since 1979 of the Spanish Socialist Workers' Party (PSOE). In 1995, López Gavela did not run and the PP gained three seats, making Álvarez mayor. As mayor, he had factories opened in the city to counteract the decline of the mining industry.[1]
In March 2001, Nevenka Fernández, the councillor in charge of finances in Álvarez's government, resigned and accused him of a year-long campaign of sexual harassment. He was convicted in May 2002.[2] In November 2003, the Supreme Court of Spain upheld his conviction but reduced the punishment upon ruling that there was not an abuse of authority; his fine was reduced from €6,480 to €2,160, in addition to €12,000 compensation to Fernández.[3]
The case resulted in the first conviction of a Spanish politician for sexual harassment.[4] In 2024, the case was portrayed in the film I'm Nevenka, with Urko Olazabal as Álvarez.[5]
In September 2010, Álvarez announced he would be running for a new party in the 2011 local elections.[6] His Independientes Agrupados de Ponferrada (IAP) won five seats and held the balance of power, allowing Carlos López Riesco [es] to become mayor.[7] On 9 March 2013, after supporting a PSOE motion to remove López Riesco and replace him with Samuel Folgueral Arias [es], he resigned per the agreement.[8] In April 2015, he announced that his party would dissolve and not contest the upcoming election.[1]