The Irish Times says Enda Kenny has intervened in the dispute – and will meet with a delegation from the SDLP, led by Alasdair McDonnell, to try and persuade them to support the DUP's call for the Assembly to be adjourned for talks.
The ultimatum from Northern Ireland's First Minister expires at the end of the day.
Peter Robinson's warned his Democratic Unionist ministers will resign if his demands aren't met – that would effectively see power-sharing collapse.
The crisis was triggered by the murder of ex-IRA member Kevin McGuigan – which has been linked to republicans.
Mr Robinson says Sinn Fein appears implicated in some way.
