The DUP is exploring possible "transitional" arrangements that might maximise party unity through a short period between the appointment of a powersharing executive and the formal start of devolved government at Stormont.
This emerged last night as British prime minister Tony Blair told the DUP that the legislation requiring the appointment of an administration by next Monday must be fulfilled. The tough message from Number 10 came as the DUP remained locked in talks with the Northern Ireland Office (NIO) and the treasury ahead of today's announcement of a new Northern Ireland Innovation Fund by chancellor Gordon Brown.
Speaking after a meeting with a DUP delegation led by the Rev Ian Paisley, the prime minister's official spokesman said the DUP had "concerns" and the British government would try to address them. However, Mr Blair "could not have been clearer" that he would not introduce emergency legislation to extend the deadline.
"The important thing is that the prime minister made it absolutely clear that he had come to a settled view, which is not going to change, which is that the 26th is the deadline and he is not going to introduce legislation to change that."
Senior DUP MPs argue that the timetable stipulated by the St Andrews Agreement has not been adhered to, given Sinn Féin's delay in holding its special ardfheis on policing. The Conservatives are willing to facilitate an emergency Bill if that were necessary to win the backing of doubtful DUP MPs like Nigel Dodds and Gregory Campbell for the formal start of powersharing at a later date.
The determination in Whitehall appears to be that any transitional arrangements would have to be found within the existing legislative framework.
However, if the possibility exists, it appears to point to the need for some amending legislation, since there is no provision for the existence of an executive in "shadow" form and the transfer of powers would automatically follow the appointment of ministers.
The assumption in DUP and Conservative circles is that, provided Dr Paisley accepts nomination as first minister on Monday, temporary amending legislation would be less of a problem for Mr Blair.
But with three or four more days of tough negotiation ahead, Number 10 and the NIO say the opposition of Taoiseach Bertie Ahern - and the absence of support among the Northern Ireland parties - makes the question of further legislation impossible.
British officials also appeared surprised by suggestions emanating from the DUP that even if Dr Paisley was ready to accept the office of first minister and to nominate DUP ministers on Monday, this might be done by letter rather than on the floor of the Assembly.