The Northern Secretary, Dr John Reid, said he hopes Mr Martin McGuinness's decision to tell the Bloody Sunday Inquiry of his role in the Provisional IRA represents a new openness in Northern Ireland society.
Dr Reid stressed that the testimony of the Education Minister would receive protection from prosecution. "I welcome the fact that Martin McGuinness is to testify, first of all because I think it helps us to get at the truth of what happened, and also because I hope it does signal a new openness.
"Any evidence that he gives there will be insulated for the purposes of that, the same way as any other person who has given evidence to the Bloody Sunday Inquiry."
However, the DUP called for the Sinn Fein MP to be prosecuted. Mr Ian Paisley jnr said: "If Martin McGuinness takes the opportunity to confess his role as an IRA member, then I think the government have a duty to ensure that, after his confession, he is arrested and charged with IRA membership. The due process of law should take its role and the Education Minister should end up in jail."
DUP minister Mr Gregory Campbell, who is an Assembly member for Derry, said he was ready to give evidence about the Sinn Fein MP's past involvement in the IRA in the city. "McGuinness has owned up to being second-in-command, but if they want to speak to me I would be happy to provide them with the information I have."
Mr Campbell said if the IRA was acting under Mr McGuinness's instructions on Bloody Sunday, questions had to be asked about his role in paramilitary activity at that time. "Two RUC men were murdered one mile from the events of Bloody Sunday three days before the march. If the IRA were acting under his instructions on Sunday, were they acting under his instructions on the Thursday? If the inquiry is going to establish the events surrounding that day, it is inconceivable that they shouldn't try to establish the events of the time."
Ulster Unionist minister Sir Reg Empey said he was not surprised at Mr McGuinness's admission: "Is there anybody who didn't know Martin McGuinness was involved with the IRA?" He called for a "full investigation" into the 1970 Arms Crisis.
The UUP MP for East Derry, Mr William Ross, said he wanted Mr McGuinness to explain what his duties and responsibilities were in the Provisional IRA.