Last month, a damaging row emerged between two top Sandinista officials, Daniel Ortega, the former Nicaraguan president who heads the radical faction, and Sergio Ramirez, his former vice-president and now leader of the party moderates. The row has been simmering for about a year, as moderates call for the the party to curb revolutionary rhetoric and shift to the centre. The infighting has splintered the Sandinista movement and the growing power struggle could split the party in two.
Mr Cardenal, a former minister of culture under the Sandinistas, who was publicly chastised by the Pope for his role in government, said he was leaving the party because Mr Ortega and his supporters would not allow moderates a voice. 'The truth is that a small group, headed by Daniel Ortega, has taken over the Sandinista Front,' Mr Cardenal said. 'This is not the Sandinista Front we joined.'
The Sandinistas were in power for almost 11 years after overthrowing the Somoza family dictatorship in 1979. They were ousted in 1990 elections, won by Violeta Chamorro's right-wing UNO coalition, following nearly a decade of war with US-backed Contra rebels.
Mr Ortega and Mr Ramirez are widely seen as the main rivals to run as the Sandinista presidential candidate in the 1996 elections. But the damaging internal bickering may ruin any chance the party has of returning to power.