London has not ruled out the possibility of a further suspension of the institutions established under the Belfast Agreement ahead of the British general election.
This emerged last night despite Mr David Trimble's apparent readiness to lead the Ulster Unionists into the election as serving First Minister in the power-sharing Executive.
In a determined move to pre-empt any unionist attempt to force a second suspension, the SDLP has placed the "protection of the institutions" alongside decommissioning, demilitarisation and policing as the fourth issue to be resolved in the ongoing negotiations.
The present indications are that the other parties will find it impossible to resist the proposal by the SDLP leader, Mr John Hume, for a round-table summit meeting of all the pro-agreement parties.
There is speculation that this could coincide with the expected enforced cancellation of next Friday's scheduled meeting of the North-South Ministerial Council in Dublin.
However, despite consistent reports that the ongoing negotiations are largely focused on policing, The Irish Times understands there is as yet no deal on the table in respect of IRA decommissioning.
And it now seems clear the British government is taking a much less relaxed view of Mr Trimble's electoral prospects than some of those closest to the Ulster Unionist leader and First Minister.
Despite republican and nationalist suspicions, authoritative sources insist Mr Trimble does not intend to force a second political crisis and a repeat of last February's suspension.
Even if the decommissioning issue remains unresolved, Mr Trimble and his key strategists apparently calculate that his best hope is to fight the election, as one source put it, "as the man who secured comparative peace, delivered devolution, got rid of Articles 2 and 3, and continues to carry the challenge to Sinn Fein".
It also appears Mr Trimble has rejected the advice of some colleagues who have been urging him to use new electoral rules to effectively disown officially-selected Ulster Unionist candidates who refuse to sign up to his election manifesto.
Under new Westminster legislation governing the registration of political parties which came into effect last week, party nominating officers are required to issue certificates authorising candidates seeking election under the registered party label.
Mr Trimble is registered with the electoral commission as the UUP's nominating officer, and some colleagues have argued he could use the new rules to nominate pro-agreement candidates to stand against sitting UUP MPs such as the Rev Martin Smyth and Mr Jeffrey Donald son.
However, while pro- and anti-agreement sources privately agree Mr Trimble "would probably love to do it", it is understood the idea has been rejected as "the nuclear option which would destroy what remains of the party".
Despite the apparent buoyancy of their Democratic Unionist challengers, there is also confidence among some Trimble supporters that the anti-agreement faction may suffer casualties in the general election, while a possible pact with the Alliance Party could strengthen the prospects of some of Mr Trimble's allies.
However, London fears a formal review of the agreement may not be enough for Mr Trimble to reassure unionist voters and is pressing still for a "big picture deal" on weapons and policing.
Asked if suspension remained an option, one British source last night said: "We don't want to, but if push comes to shove our position would be the same as last February."