An amendment to the Criminal Justice Bill allows private sector workers at the CRB the right to access the PNC directly rather than having to ask a civil servant to get the information for them.
The amendment, to be debated next week, will allow staff of a company working in partnership with the CRB to work on the PNC, which holds the criminal record data. Capita holds the contract.
A Home Office spokesman said the change merely meant suitably vetted staff would have access to the PNC. The move is linked to another clause, which renders anyone improperly disclosing information subject to a £4,000 fine or a year in prison. Civil servants improperly disclosing information would also be in breach of the Official Secrets Act.
Earlier this month, Liberal Democrat MP Paul Burstow claimed in a parliamentary debate that the CRB's IT systems provided by Capita may not have been fit for purpose.
Clarke said the proposed legislation would "improve the efficiency" of the CRB by allowing Capita staff to access the PNC directly under strict controls.
"I am in favour of anything that helps the CRB to do a more efficient job and cuts down on bureaucracy. I do not think this represents a major infringement of civil liberties,'' he added.