The Rev Ian Paisley's Democratic Unionist Party will surprise the political world today by defining the circumstances in which it would share full cabinet power with Sinn Féin at Stormont.
And the now dominant unionist party will unveil innovative proposals designed to break the immediate political deadlock in Northern Ireland by way of a "voluntary coalition" government including the SDLP - or, alternatively, by initially permitting the Assembly to operate by way of a weighted majority voting system.
At the same time, the DUP will confirm its intention to block the return of "mandatory" power- sharing government including Sinn Féin until it is satisfied the IRA has undertaken the "acts of completion" repeatedly demanded by the British Prime Minister, Mr Tony Blair.
Sinn Féin and the SDLP are expected to react with suspicion, if not outright hostility, to plans which some have dismissed in advance as an attempt to restore "majoritarian" rule to Stormont. However - while doubtful about the nationalist and republican response, and in no doubt about the difficulties ahead - the British and Irish governments are clearly encouraged that the self-styled "traditional unionist" party is crossing a huge political and psychological barrier in accepting that any devolved government in the North must be acceptable to a majority of both communities there.
Potential Ulster Unionist critics, meanwhile, may be disappointed to discover that - contrary to some recent press reports - the DUP does not propose to lower its demands in respect of IRA decommissioning in exchange for a lower level of devolution.
The driving principle of the DUP plan is that full power should be devolved to the Assembly and not, as last time, to individual and largely unaccountable ministers.
Assuming the SDLP remains unwilling to enter a voluntary coalition government without Sinn Féin, the DUP plan would enable the Assembly to discharge its business across a range of issues by way of practices and procedures which apply in the existing local government model.
Dr Paisley and his deputy, Mr Peter Robinson, will outline their proposals at a media presentation in Belfast this morning before launching a widespread consultation with the traditional Loyal Orders, Protestant Church leaders and community and other representatives in the wider unionist community over the coming weeks.
During a one-hour meeting in Downing Street yesterday Mr Robinson gave Mr Blair what was described as a "power-point presentation" of the key elements of the DUP plan, which represents an opening negotiating position, and the first instalment of its overall thinking on an alternative to the Belfast Agreement.
The official position was spelt out by the Prime Minister's official spokesman, who said the government would reflect on the DUP presentation, and was pleased that the DUP and others were "being positive" in their approach to the review of the Belfast Agreement formally begun last Tuesday.
However, it became clear in Whitehall last night that the DUP blueprint is at least considered "a serious piece of work", although sources acknowledged "a huge question mark" was hanging over the reaction of the other parties.
The DUP is clearly hoping they will not rush to judgment.