Nationalist party Sinn Fein raised fresh doubts over plans for power-sharing in Northern Ireland on Tuesday by saying it would reconsider whether to hold a special debate on policing in the British-ruled province, according to Reuters. London and Dublin want a power-sharing assembly to resume operations on March 26, but it cannot do so unless nationalists give their backing to a legal system they have long viewed as biased in favour of pro-British unionists. A Sinn Fein special conference to discuss policing this month was conditional on positive noises from the DUP but the DUP has refused to offer encouragement, saying acceptance of law and order should be a given. Speaking after a meeting of his party's leadership in Dublin, Sinn Fein's chief negotiator Martin McGuinness said there was "deep concern" about a lack of clarity from the pro-British Democratic Unionist Party (DUP) about power-sharing. "We have a very serious situation," McGuinness told reporters.