Mr Chris Patten's Independent Commission on Policing has rejected Democratic Unionist Party claims that it lacks independence and is "bankrupt" to the Belfast Agreement.
The commission held its first public hearing in Belfast yesterday and was promptly accused by the DUP justice spokesman, Mr Ian Paisley jnr, of being a puppet of the Agreement.
Mr Paisley said it was the perception of DUP supporters that the commission, headed by Mr Patten, a former Hong Kong governor, would arrive at predetermined conclusions on the future of the RUC that would accord with the principles of the agreement.
The only solution that republicans would accept would be the disbandment of the RUC, he told the commission.
A commission member, Sir John Smith, said the claims about lack of independence raised his hackles.
"I have never considered myself a puppet," Sir John, a former deputy commissioner of the London Metropolitan Police, told Mr Paisley.
"If anybody bothered to look at where we came from, what we have been doing, the way we react to situations, everybody can see that we value integrity and our independence.
"Anybody who suggests that we lack independence doesn't know us. If they don't know that we are fiercely independent, I don't suppose I, or anybody else, can convince them," he said.
Mr Paisley refused to retract his claim and said it was now up to the commission to prove him wrong by confirming its independence. He said he would have been failing in his duty to his electorate if he had not advised the commission of "their views, fears and suspicions".
A crucial element of the commission's remit is to devise methods of attracting more Catholics into the force, which is currently 92 per cent Protestant. Mr Paisley said the RUC must retain the capability to deal with any fresh outbreak of paramilitary violence. Equally, recruitment must always be determined on merit alone.
Mr Gregory Campbell, the DUP security spokesman, said that any changes to the RUC composition must be through "evolution rather than revolution".
Radical measures to bring more Catholics into the force would only serve to antagonise unionists and divide the community even further.
The DUP also opposed some suggestions that a two-tier policing system be created. Mr Campbell said it would be intolerable if former paramilitary prisoners were absorbed into the force to carry out community policing.
"It has been mooted in some circles that some of those terrorists, killers, murderers and gangsters who have been released as a result of the Belfast Agreement may be eligible for some form of participation in a community policing role," Mr Campbell said. This would create intense anger in the community, he added.
Mr Tom Gillen, of the Irish Congress of Trade Unions in the North, told the commission that in any future policing system the chief constable should be made more accountable to the Police Authority.