The North's First Minister is meeting British Prime Minister David Cameron tonight - to try to resolve the political crisis at Stormont.
Peter Robinson's DUP want the assembly suspended for the time being, to allow urgent talks about the IRA.
The PSNI has linked the group to the recent murder of former IRA member Kevin McGuigan.
Speaking ahead of the meeting at Downing Street, Mr Robinson said he wanted two things:
The meeting comes as Sinn Féin lashed out at An Taoiseach Enda Kenny for what it says are "offensive and vindictive" remarks about the peace process.
Gerry Adams has said the PSNI needs to be allowed to investigate crimes in the North without political interference.
"The Taoiseach needs to resist the temptation to play politics with the brutal murders of Jock Davison and Kevin McGuigan in Belfast," Mr Adams said.
“These are very clearly matters for the criminal justice system and the PSNI should be allowed to pursue their investigations without political interference".
“The IRA is gone away and Mr Kenny knows that full well. The Taoiseach needs to reflect on his responsibilities to the peace and political processes and should refrain from such offensive and vindictive interventions".
Earlier, Mr Kenny said Sinn Féin needed to do more than simply condemn criminal activity.
And he told reporters that police needed every resource to find the culprits.
The Foreign Affairs Minister has challenged all five major parties in the North to begin new talks on the future of the peace process.
Charlie Flanagan says the Government will play a fundamental role in facilitating any talks if the parties agree to take part:
The talks between David Cameron and Peter Robinson come on the day the Ulster Unionist Party (UUP) officially leaves the Northern Executive over allegations that IRA members were behind the murder of Kevin McGuigan in Belfast.
Earlier, the Garda Commissioner briefed Mr Kenny and senior ministers about the Provisional IRA and security issues.
Noirin O'Sullivan gave her assessment of the current situation amid crisis meetings in Dublin and London to try to save the Stormont institutions.
Here the Government has described revelations about alleged IRA criminality as very serious, and a report was sought from the Garda Commissioner.
