Legislation to suspend Northern Ireland's fledgling power-sharing government is due to be rushed through the House of Commons as prospects for an end to the paramilitary disarmament impasse remain bleak.

Political institutions achieved through the peace process will be effectively frozen by the weekend unless the IRA agrees to decommission its weapons.

Sinn Fein President Gerry Adams is meeting UK Prime Minister Tony Blair in Downing Street before the Commons debate starts, in what is thought to be a last ditch attempt to stop the suspension going ahead.

Sinn Fein requested the meeting at which the party's assembly executive ministers Martin McGuinness and Bairbre de Brun are also present. In an unusual move, the Sinn Fein delegation entered Number 10 by a side door and by-passed the media.

Downing Street has described the meeting as "marking time".

Government moves to re-introduce direct rule from London, come in the wake of the bomb attack on a hotel in County Fermanagh.

The republican splinter group, the Continuity IRA, admitted the bombing and warned it would continue its campaign of violence.

Legislation to suspend the assembly is expected to clear all of its Commons stages on Tuesday night and the House of Lords by Thursday, in time to receive Royal Assent on Friday.

That would enable Mr Mandelson to suspend the executive and assembly before Saturday's crucial meeting of the ruling council of David Trimble's Ulster Unionist Party.

The UUP has warned that unless the IRA starts to decommission its guns and weapons, it will effectively collapse the executive by walking out.

The government's planned suspension of the assembly is designed to prevent Mr Trimble's resignation which, it is feared, would trigger a collapse of the Good Friday Agreement, if not the peace process itself.

But meetings to try to find a way out of the crisis have been held, even while the legislation is being prepared.

After meeting the Northern Ireland Secretary Peter Mandelson on Monday, Mr Adams said the impasse over arms decommissioning was based on a "bogus premise".

But the Ulster Unionists have said they cannot continue in government with Sinn Fein, which is linked to the IRA, unless there is paramilitary disarming.

Sinn Fein is opposed to any moves to suspend power-sharing in the province, warning that it would make the chances of achieving IRA disarmament less likely than ever.

In a rare move Sinn Fein Mid Ulster MP Martin McGuinness and health minister Bairbre de Brun may watch the suspension debate in the Commons gallery.

Sinn Fein will hold a press conference at Westminster later on Tuesday to protest against the suspension of the assembly.

Republicans have been under intense pressure, particularly from the Irish Government, to break the impasse over decommissioning after last week's report by General John de Chastelain concluded that the process had not begun.

Meanwhile, a Democratic Unionist party bid to propose a motion to exclude Sinn Fein from the assembly has failed.

The move by the anti-agreement party did not receive the 30 signatures from assembly members needed to hold a debate.