Sinn Fein have criticised comments made by the Conservative Northern Ireland spokesman that the Executive should be collapsed if there is no IRA decommissioning.

Andrew Mackay said if there was no movement by the end of January or shortly after, that the Executive would be suspended.

Sinn Fein national chairman Mitchel McLaughlin said the remarks were unhelpful.

"His comments throughout his short career as an opposition spokesperson on the north have reflected a singularly uninformed attitude.

"I think he is more concerned with harassing the British Labour Party in government.

"I don't think he acts out of any concern for the unionist community or the unionist party for that matter and I think he is by instinct opposed to the peace process," Mr McLaughlin said.

Mr Mackay said on a visit to Londonderry on Friday that the Northern Ireland peace process was reaching a crucial time.

Canadian General John de Chastelain, who heads the independent decommissioning body, is due to give his vital assessment on illegal arms before the end of January.

Mr Mackay told BBC Radio Ulster: "I would give everybody a few extra days grace, but you cannot keep on doing it."

"You cannot keep on saying: Deadline over. Move on to the next deadline.

"I think it is untenable for the executive to continue far after the end of the month if there is no proper, verifiable decommissioning on the part of the IRA and hopefully, on the part of the so-called loyalists as well."

The issue of decommissioning is the final piece of the jigsaw of institutions to be set up under the terms of the 1998 Good Friday Agreement.

The Ulster Unionist ruling council endorsed a peace deal last November which allowed devolution to take place before the handover of terrorist weapons.

It is meeting again next month to review its decision to go into government with Sinn Fein.

Mr Trimble, the party's leader, has threatened to resign and collapse the institutions if the IRA have not started to decommission by that date.

The peace deal supported by the Ulster Unionists broke the deadlock in the stalled peace process.

It was put forward by former US senator George Mitchell, after his 10-week review of progress of the Good Friday Agreement.