The prime minister has rejected Democratic Unionist Party claims that full IRA decommissioning has not taken place.

The DUP's David Simpson raised the subject during Tony Blair's weekly questions session in the Commons on Wednesday, referring to the discovery of 10,000 bullets in woods near Sligo in the Irish Republic on June 1.

He said a senior police officer in Ireland had confirmed the ammunition was IRA property.

"Would you agree with me now that the full decommissioning that was promised to the people of Northern Ireland in fact did not happen?," he asked.

Blair replied: "I can't agree with that, no."

He said the final say on decommissioning ultimately rests with the Independent Monitoring Commission.

"Throughout the whole course of the peace process over these last few years we have sought to get some form of independent verification about whether the claims of the IRA, or indeed the claims of others, are justified or not," he said.

"For that reason we introduced the IMC. They will look at all the evidence including statements that have been made by those in the republic or indeed those in the Police Service of Northern Ireland and they will make up their minds as a result of that.

"But we have got in the end to make our judgement on the basis of what that IMC says.

"If we do not do that then we are losing the essential objectivity which is the only way that you can determine claim or counter claim.

"There are claims and counter claims made on all sides of this issue.

"There is only one way of determining them finally and that is the process that we set up and actually that [the DUP] supported at the time."

In April, the IMC said the amount of IRA arms not decommissioned was "not significant" compared to the amount handed over.