Private healthcare providers are lobbying to come under the remit of the Commission for Health Improvement and the National Institute for Clinical Excellence.
In a submission to the health select committee's inquiry into the regulation of private care, the Independent Healthcare Association says there should be a single system of regulation for the NHS and private sector.
IHA spokesman David Lucas said:
'Looking at current government policy and what they are doing, the obvious thing is to make organisations like NICE and CHI and the ombudsman national bodies instead of NHS bodies.'
Two of the largest independent healthcare providers, BUPA and PPP Healthcare, have told MPs they would like to come under the aegis of NICE and CHI.
They have also called for all private healthcare providers to come under a unified monitoring and complaints procedure.
A PPP spokesperson said: 'We feel it is important that as patients move between the two systems there is a common framework for looking after them.'
Mr Lucas said the IHA felt a single regulatory system would be cost-effective and encourage benchmarking and co-operation between NHS and private sector organisations.
But NHS Confederation policy adviser Tim Jones said CHI could be stretched too far by taking on the task.
'CHI will have powers to fine and claw back money from the NHS but it is not clear what powers it will have, if any, over the private sector, ' he said. 'There is a danger that the jam could be spread too thin if they took on a role.'
The confederation has not submitted evidence to the inquiry, arguing that quality and monitoring arrangements are in place for the private work that goes on in NHS hospitals - the biggest providers of private care.
Last year, former health minister Alan Milburn rejected a call by BUPA's medical director, Andrew Vallance Owen, for the company to come under the remit of NICE and CHI. He said they were created to look after NHS patients.
But the Association of Directors of Social Services has joined the calls for state regulation to be extended to the private sector.
In its submission to the inquiry, the ADSS says nursing agencies should be brought within the remit of the eight regional commissions for care standards proposed in the government's social services white paper.
It also argues that regulatory regimes for acute and nursing care should be separated, so a single framework can be created for nursing and care homes.
And it says 'directly provided NHS long-term care should be subject to regulation on the same basis as independent healthcare provision'.
The British Medical Association used its submission to the inquiry to call for more stringent regulation of private healthcare.
It argues that it is 'wholly wrong' for doctors in private practice to be judged by lesser standards than colleagues in the NHS.