Pressure from Provisional IRA and Sinn Fein grassroots members has forced the party leadership to stop condemning attacks by dissident republicans, according to sources in the organisations.
Sinn Fein is refusing to condemn Wednesday's bomb attack on Castlewellan RUC station in Co Down, which has left a police officer critically ill. This is in stark contrast to Sinn Fein's previous condemnations.
"The policy change has been forced on Sinn Fein," a republican source said. "There was growing dissatisfaction among grassroots that the leadership was condemning these attacks."
Sinn Fein started condemning attacks by dissidents after the "Real IRA" bombing in Omagh, which killed 29 civilians two years ago. Until Tuesday, every dissident attack since had been condemned.
The Education Minister, Mr Martin McGuinness of Sinn Fein, condemned the "Real IRA" bombing of Stewartstown RUC station in July. The following month the party condemned an attempted "Real IRA" bombing in Derry.
However a Sinn Fein representative, Mr Mick Murphy, refused to condemn the Castlewellan attack. He said his party wanted an end to all violence but, when asked to condemn the bombing, added: "I am not into condemning anything."
A Sinn Fein representative confirmed that Mr Murphy had accurately represented the party's view, but claimed this was not a change from its previous position.
Dissident republican sources have described the Castlewellan attack as highly significant. It is the first attack the "Real IRA" has carried out in the North in two years which was clearly and deliberately designed to kill.
"It is a sign that the `Real IRA' is stepping up its campaign," the source said.