Plummeting relations between Sinn Fein and the DUP have lead to a new row over the first republican becoming Speaker of the Assembly.
Sinn Fein has accused its power-sharing partners of playing "silly buggers" over the historic takeover – which should have already happened by now.
The party's Mitchel McLaughlin had been expected to succeed the DUP's William Hay as part of an arrangement reached under former First Minister Ian Paisley and Deputy First Minister Martin McGuinness.
But Sinn Fein has said the DUP has insisted more recently it never agreed to the timing of the move, which will now not happen until September at the earliest.
The handover appears to be the latest issue joining the growing list of stand-offs between the two main parties – including welfare reform, the education and skills authority, and the collapse of the Maze peace and reconciliation centre. Together they point to the spreading paralysis of government and feed fears that the coalition Executive could still topple, seven years after the restoration of devolution.
A senior SF source claimed: "The DUP have been playing silly buggers over this, as with so much else. We had anticipated that Mitchel would be in position in April but the DUP has told us it did not agree with the timing and never agreed the timing.
"To that extent it is our own fault. We never tied them down to the exact date but we did expect they would honour the principle that the two main parties would share the Assembly term equally.
"Now even with the extra year being added on the term (the next Assembly elections are in 2016) it is still more than half way through the period.
"But we are optimistic that it will be sorted out and that Mr Hay would be standing down in September."
A DUP spokesman, however, said: "The Speaker will choose his time and date for standing down. There will need to be an amendment to Standing Orders to enable the change. The DUP has discussed this with other parties, including Sinn Fein."
Donegal-born Mr Hay, who has been an elected DUP politician since the early 1980s, had initially been expected to be replaced by veteran Sinn Fein activist Francie Molloy.
But instead the party chose Mr Molloy to fight its Mid-Ulster seat at Westminster after Martin McGuinness stood down as part of moves to end double-jobbing. Mr Molloy retained the seat despite a joint DUP/UUP candidate.
Mr Hay may go to the Lords.
South Antrim MLA Mitchel McLaughlin emerged as Sinn Fein's choice to become the first republican Stormont Speaker after Francie Molloy became Mid-Ulster MP to replace Martin McGuinness. Mr McLaughlin is a former general secretary and national chairperson, a major contributor to the Sinn Fein document Towards a Lasting Peace in Ireland and negotiator of the Good Friday and St Andrews agreements.