David Trimble has told the prime minister that the latest Northern Ireland peace talks lack credibility.

The Ulster Unionist Party leader emerged from Number 10 to tell reporters that he would not enter into further talks that involved Sinn Fein.

And he added to the crisis in the peace process by urging the Democratic Unionists to follow his lead and abandon the current review process being conducted by Northern Ireland secretary Paul Murphy.

The latest row follows a police operation in Belfast that thwarted an alleged IRA attempt to abduct a republican rival.

Trimble said that this event vindicated his decision to abandon the power sharing executive, saying that recent events would have "brought it down" in any event.

The UUP leader said he told Tony Blair that he had "a duty to act".

"There is no point in continuing with the review when it is clear that the underlying problem is not resolved and indeed that the republicans have not come to the point of making the crucial decision on change, and on change towards peace and democracy," he said.

Trimble said the prime minister was still considering the matter.

"I hope he will act in a way that restores credibility to the process, but I cannot tell you at this stage whether he will or he will not," the former first minister added.

Trimble also said the DUP should not "abandon the need for there to be a clear commitment to peace and democracy".

He said that this would mean leaving any talks process that includes Sinn Fein.

Sinn Fein scorn

Trimble pledged that despite the crisis, the UUP would continue to negotiate with other parties.

But Sinn Fein attacked the latest move by Trimble, arguing that loyalist attacks on Catholics were more frequent and should instead be the focus of talks.

"Unionist leaders need to accept their responsibility to use their influence to bring an end to sectarian attacks on Catholics emanating from their community," said assembly member Bairbre de Brun.

"The reality is that the IRA poses no threat to the peace process."