A battle of political wills between the DUP and Northern Ireland Secretary Peter Hain is looming in the countdown to next Monday's "deadline" for the restoration of powersharing at Stormont.
This became clear last night as authoritative DUP sources confirmed the scale of potential internal opposition to party leader the Rev Ian Paisley concluding the deal - as he is believed to want to - by the March 26th date set by the British and Irish governments.
The Irish Times has been told by pro-agreement sources that a crucial meeting of DUP officers later this week is "too close to call", given the determination of four of the party's nine MPs - Nigel Dodds, Gregory Campbell, William McCrea and David Simpson - to seek to at least delay the formation of a new executive until May.
Unless the officer team is broadly agreed, the sources said it would be impossible to secure the party executive's backing for the commencement of devolved government next Monday.
That gloomy assessment followed a weekend admission by Mr Hain that devolution is not yet "a done deal", coupled with a warning to the DUP that there could be "no ducking or dodging" next week's deadline.
London and Dublin will be hoping the DUP is engaged in brinkmanship ahead of tough negotiations.
These will see Dr Paisley and other party leaders in Downing Street for talks with British prime minister Tony Blair on Wednesday.
That meeting will be followed on Thursday at No 11, in the ongoing negotiation with chancellor Gordon Brown about the so-called "peace dividend" to boost a new partnership administration.
However, enthusiasts for an early agreement have again said that DUP deputy leader Peter Robinson - expected to be finance minister in the new administration, and a likely future first minister - will be a critical figure in assessing the impact for long-term party unity of a decision to meet the British-Irish deadline.
It is also being stressed by allies of Mr Robinson that he has yet to be convinced that the party's terms - in respect of the financial package and the question of "sanctions" to be deployed against Sinn Féin in the event of any future "default" by the IRA - can be met in the time available.
Senior British sources appear confident they can satisfy the DUP's stated requirements during this week's negotiations, and that Dr Paisley, with his position hugely strengthened by the Assembly election results, will feel no need to allow issues about future party management to get in his way.
The British calculation also is that North Belfast MP Nigel Dodds is unlikely to maintain his opposition should Dr Paisley push the issue to a positive conclusion this week, and that he would in all probability accept a senior ministry in a new executive.
However, if that confidence should prove misplaced, DUP sources say the week could still end with the party leadership appealing to Mr Blair to overrule Mr Hain and for an emergency Bill to go before the Commons next week extending the life of the Assembly, and possibly allowing for the appointment of an executive which would not "go live" until a stipulated date in the summer.