The Good Friday Agreement would have been killed off by the Northern Ireland Office if the civil servants had not been kicked out of the fragile negotiations in the final stages, a former First Minister has revealed.
David Trimble, now Lord Trimble, told a Westminster committee that he regarded most people in the NIO with contempt.
The former Ulster Unionist leader, who was later jointly awarded a Nobel peace prize for his key role in negotiating the Agreement, was giving evidence at the inquiry into the controversial letters of assurance given to republican fugitives by the Government. Lord Trimble, a Conservative peer, told the Northern Ireland Affairs Committee of MPs that he did not have a good relationship with the NIO dating back to the time of the Agreement.
He claimed: "Most of the people there I held in contempt.
"We only got an agreement (in 1998) because they were excluded from the negotiations in the final week. We would not have had an agreement if the NIO had still had charge of the process."
Lord Trimble also accused former premier Tony Blair of keeping him in the dark about the sending of the so-called 'letters of comfort' to more than 200 on-the-runs (OTRs) which assured them they were not wanted by police.
The OTR letters came to light in February when the trial of John Downey for the 1982 IRA Hyde Park bombing, which killed four soldiers, was halted because he had mistakenly received one of those letters when the Metropolitan Police was looking for him.
Mr Downey denied involvement in the attack.
"I was quite hurt by the fact that there we were, we had so many meetings with the Secretary of State, speaking to the Prime Minister and we approached those meetings in a candid manner, to find out that they were deliberately keeping something from us," the former MP for Upper Bann said.
"There were no hints made or indications in those conversations that led us to believe nothing was being done on the OTR front. Clearly the intention was to keep the information from us."
Lord Trimble said his general approach was that he believed in the cock-up theory of history as opposed to conspiracy theories.
Under an administrative scheme drawn up during the peace process, the on-the-runs (OTRs) were told by the Government that they were no longer wanted for paramilitary crimes committed before the 1998 Good Friday Agreement.
The messages did not rule out future prosecutions if new evidence emerged.
Members of the Northern Ireland Affairs Committee have already heard that 95 of 228 republicans who got letters of assurance from the Government have been linked to 295 murders.
The watchdog is conducting an inquiry into the OTR deal.