What now for Northern Ireland?

Time is rapidly running out for the deadlocked political process in Northern Ireland. BBC News Online explains what could happen next.

The deadline

Ulster Unionist leader David Trimble resigned as First Minister on 1 July 2001.

The legislation that established the assembly provides for this eventuality by giving the institution six weeks in which to choose a replacement first minister. That six-week period comes to an end on Sunday 12 August.

If the prime minister of the UK or Ireland resigned, the respective legislatures would not implode because they do not depend on the position of one person or one party.

However, the power-sharing arrangements of the Northern Ireland Assembly demand cross-community support for legislation to be passed.

Therefore, when Mr Trimble resigned, the SDLP Deputy First Minister Seamus Mallon ceased to hold office at the same time.

However, a tactical move by Mr Trimble's party at the time of his resignation prevented the immediate collapse of the institutions.

The UUP designated Sir Reg Empey to exercise Mr Trimble's functions ahead of the 12 August deadline.

This has allowed Mr Mallon to also exercise the functions of his office, even though he no longer holds the post, thereby keeping the executive in office.

Scenario one: Trimble re-elected

Time for this option effectively ran out on Friday morning. David Trimble would have had to return to his party with a deal, seek their support and then his re-election as first minister.

Mr Trimble would have required the support of a majority of both unionists and nationalists in the assembly to return to office.

But Mr Trimble had already pledged to his party that he would not sit in government unless the IRA had begun to decommission weapons.

Without that move, it remains virtually inconceivable that he can win the support of his party colleagues unless he can convince them that something dramatic has happened.

Furthermore, time effectively ran out for the assembly's presiding officer to call a meeting of its members because protocol states that they require 24 hours notice.

Scenario two: Suspension

In February 2000 the then Northern Ireland Secretary Peter Mandelson suspended the institutions and reinstated direct rule from London to prevent Mr Trimble carrying out a threat to resign over decommissioning.

This move was met by a mixture of fury and disappointment from nationalists and the Irish government.

His successor, John Reid, is unwilling to travel the same road again, given the uncertainty it creates.

Nobody knows what would happen in the political vacuum that a suspension would inevitably create. Would it lead the parties to drift away from the Good Friday Agreement, endangering the entire process?

Another contentious issue, say nationalists, is that a suspension requires the use of legislation introduced by Westminster subsequent to the Good Friday Agreement - legislation which did not have cross-community support.

However, there is another option on the suspension front.

A loophole in the legislation means that the Secretary of State could suspend the institutions for just one day. This, in theory, would then create a second six-week deadline and perhaps a breathing space for all to take stock.

If there was an open-ended suspension, a review of the political process would probably have to take place before any progress could be made.

Scenario three: Elections

If the British government believes that it can make no further progress, Northern Ireland Secretary John Reid could choose not to suspend the assembly and instead allow an election to take place, as the original legislation sets out.

The parties would then be forced to return to the electorate and seek a new mandate for their positions, perhaps achieving a result that will break the impasse.

However, of all the scenarios, this is the one that has the greatest element of uncertainty.

If an election for the 108 seats followed the trend of the 2001 general and local elections, the most moderate of the four main parties, the Ulster Unionists and the SDLP, would lose ground to Sinn Fein and the anti-agreement Democratic Unionists.

This, many fear, would mean that it would create an even worse situation in which the assembly would be polarised and unable to elect a new First Minister and Deputy First Minister.

There is also a further complicating factor of voter fatigue.

Northern Ireland's political crisis has rolled on all year as the parties jockeyed for position ahead of the general election. The election itself became a de facto second referendum on the Good Friday Agreement.

It is by no means clear that the voters who have been watching all this take place would look favourably on being asked to go back to the ballot box again.