Changes must be made to the Good Friday Agreement to ensure its survival, the Northern Ireland First Minister David Trimble has said.

Speaking at a Westminster news conference on Wednesday, the Ulster Unionist Party leader called for measures to ensure that only those people committed to exclusively peaceful means should be in government.

Mr Trimble said Mr Blair needed to bring about changes to ensure that the prime minister's promises, made at the time of the referendum, were kept.

The UUP leader held up a picture of Mr Blair making those pledges, and said it was time for him to keep his word.

Tony Blair: PM's promises to NI were raised by Mr Trimble

He said it was essential that the prime minister acted to stem the "dangerous loss of confidence" that was now developing.

"We need changes in the exclusion mechanism, I am not going to say exactly what they are," he said.

"Something needs to be done and done soon if there is not to be a catastrophic loss of confidence in the institutions.

'Unsustainable'

"The way to sort it out is to ensure the Agreement has bite. Once you put the proposals into place, I think that will work. I think Sinn Fein will change."

He said violence was still being "organised, orchestrated and planned" by mainstream republicans with links to Sinn Fein.

Party colleague Jeffrey Donaldson, who has been a strong opponent of the Agreement also called for action from Mr Blair.

"If confidence continues to be undermined at the rate that it is, it will be unsustainable in terms of Sinn Fein's presence," he said.