Irish Republican Army dissidents on Sunday threatened to kill top Sinn Fein politician Martin McGuinness and resume attacks in England as part of their efforts to wreck the IRA cease-fire and Northern Ireland power-sharing. An Easter statement from the outlawed Real IRA distributed to Irish media branded McGuinness a traitor because he holds the top Irish Catholic post in Northern Ireland's power-sharing government with British Protestants. The statement warned McGuinness - a former IRA commander - that "no traitor will escape justice regardless of time, rank or past actions. The republican movement has a long memory." McGuinness offered no immediate response. He previously has appealed to the public to tell police about dissident IRA activities and said extremist threats won't deflect him from cooperating with Protestant past enemies. The Real IRA also claimed responsibility Sunday for a long-disputed killing of a Sinn Fein official who was exposed in 2006 as a British spy. Denis Donaldson, Sinn Fein's former chief legislative official inside the power-sharing government, was shot to death at his rural hideaway in northwest Ireland four months after he confessed his duplicity at a Sinn Fein news conference. An Irish weekly newspaper, the Sunday Tribune, published an interview with an unidentified Real IRA spokesman in which the official warned that the group intends to resume attacks in London. The group has in the past issued statements via the Sunday Tribune. The Real IRA last launched attacks in the British capital in 2000, when it struck the headquarters of the MI6 spy agency with a rocket and detonated a car bomb outside a British Broadcasting Corp. office. The Real IRA killed two unarmed British soldiers March 7 as they collected pizzas outside a Northern Ireland army base. They were the first killings of troops in the British territory since the IRA's 1997 cease-fire. Another splinter group, the Continuity IRA, killed a policeman March 9 in what was the first killing of a police officer since 1998, the year of Northern Ireland's Good Friday peace accord. The dissidents oppose the IRA's 2005 decisions to renounce violence and disarm, and remain committed to the belief that Northern Ireland must be forced out into the Irish Republic. The Good Friday pact reinforced the right of Northern Ireland to remain in the United Kingdom as long as most of its residents prefer this.