MEXICO CITY  The Cuban government on Wednesday agreed to release 52 political prisoners in the coming months, a dramatic move that may ease international criticism as well as save the life of a prominent dissident who has been on a hunger strike for four months to push for the liberation of inmates.

The announcement, which would reduce the number of prisoners of conscience on the island by about a third, came after a meeting that included President Raúl Castro of Cuba; Cardinal Jaime Ortega, the archbishop of Havana; and the Spanish foreign minister, Miguel Ángel Moratinos.

The prisoners to be released, five initially, and then, 47 others, were all detained during a major crackdown on dissent in 2003, when the government of President Fidel Castro rounded up 75 activists and journalists who were accused of acting as “mercenaries” on behalf of the United States.

Of the original 75 detainees, some completed their sentences or were released on health grounds. Those who remained behind bars turned into potent symbols to Cuba’s critics of the government’s heavy-handed approach to dissent.