Sinn Fein has fulfilled its obligations in government and now wants unionists to do the same to avoid a political crisis, Northern Ireland Deputy First Minister Martin McGuinness said today.
With the region's power-sharing government on the verge of possible collapse, his comments came as he prepared to enter a crunch meeting with Democratic Unionist Party (DUP) leader Peter Robinson.
The British and Irish Premiers are holding talks in London today on the growing crisis as the DUP and Sinn Fein seem unable to agree a deal on devolving policing and justice powers from Westminster to the Assembly.
Mr McGuinness claimed that, while his party had backed new policing structures after the 2006 St Andrews agreement which paved the way for power-sharing, the DUP had yet to fulfil its commitments.
"Within three months of the St Andrews agreement we in Sinn Fein moved forward decisively on the issue of policing, took what was considered to be an historic and monumental decision," he said.
"And we did that within three months of St Andrews... to ensure that these institutions would work.
"Three years on, three years on, we are waiting for the DUP to deliver and honour their commitments, that all of us were supposed to have signed up to under the terms of an agreement that was presided over by the Irish Government and the British Government."
The Sinn Fein representative, who hit the headlines when he branded dissident republicans traitors after they murdered two soldiers and a police officer last March, said he had worked hard to form an effective political partnership, first with the former DUP leader Ian Paisley, and then Peter Robinson.
"From the very beginning of this process... I have been at pains to make this place work," he said.
"It's been my life's work over the course of recent times because I passionately believe in power-sharing, passionately believe in all-Ireland institutions and passionately believe in working in a positive and constructive mood with all of the people that I come in contact with."
He added: "Unfortunately, we have learned that there are people within these institutions who only see the future through the prism of one section of the community - that is not a sustainable way to move forward and I am not going to be part of that."
Mr McGuinness, flanked by Sinn Fein colleagues including party president Gerry Adams, said: "I respect the mandate of Peter Robinson. I respected Ian Paisley's mandate. It is now time for them to respect ours."
Sinn Fein warned recently that if agreement cannot be reached on devolving policing and justice powers from London to Belfast, the institutions can no longer continue.
Despite a measure of agreement among both power-sharing partners in Northern Ireland that policing has to be devolved at some stage, they have sparred over when that will take place.
There is also a dispute over the handling of controversial loyal order parades.
The DUP wants to scrap the Parades Commission, which adjudicates over and places conditions on some of the most contentious marches, but Sinn Fein accused the unionist party of giving the Orange Order a talks veto.
Three years ago Sinn Fein backed the new policing arrangements in Northern Ireland, where the reformed Police Service of Northern Ireland (PSNI) replaced the Royal Ulster Constabulary (RUC).
Republicans made the move on condition that the Assembly eventually took over political responsibility for law and order from Westminster.
But with unionists insisting that the conditions must be right before completing the transfer of the powers, and with Sinn Fein demanding they close a deal, the long-running dispute has now reached crisis point.