Regulation of the NHS is in need of a radical overhaul if it is to keep pace with reforms, experts say.
The government is carrying out a review of NHS regulation
Over the next few years health care will be increasinly provided by the private sector and foundation trusts which operate outside state control.
Current NHS watchdogs and health managers said if changes were not made the concept of holding the health sevice to account would "fall apart".
The government said it was carrying out a review and would consider ideas.
At the moment the system of NHS regulation is carried out by a number of bodies, including the Healthcare Commission, Commission for Social Care Inspection, foundation trust regulator Monitor, the Audit Commission and various other bodies that monitor finances and mental health.
The government has already committed itself to merging the Healthcare Commission and CSCI.
But experts at a debate hosted by the King's Fund think tank in London on Tuesday urged the government to go much further.
Jennifer Dixon, director of policy at the King's Fund, said the moves to allow every hospital to become a foundation trust by 2008, to give GPs powers to commission service and increase private sector provision was presenting challenges for regulation.
She said there needed to be "better information for patients" and more emphasis on economics as NHS trusts are given more autonomy.
It has been widely assumed the government review will lead to a slimming down in the number of regulatory bodies, but Nigel Edwards, director of policy at the NHS Confederation, said that it did not necessarily mean less inspection.
He said the paradox was that as the NHS became more autonomous, it would probably need to become more accountable.
And Bill Moyes, chairman of Monitor, said there needed to be greater clarity.
For example, the National Audit Office, Healthcare Commission and Audit Commission all have a role at looking into finances of NHS bodies, but none can intervene.
"The present system is messy and not sustainable. Inspection can improve performance and protect patients, but if it does not function properly that role falls apart."
Mr Moyes also said the move towards a more market-based NHS meant the Department of Health would have to adapt.
"The NHS used to be state owned, but that is changing. The voluntary sector is a big provider of social care, mental health services are provided by the voluntary and private sector and the private sector is getting more involved in elective care.
"The government has to rethink its role. The Department for Health can no longer bark at people."
"I think it has to act more like a headquarters of a major insurance company, handing out the money so we get the best value, but leaving local purchasers to manage the targets."
The Department of Health said it was carrying out a regulation review for which - with the exception of the merger between the Healthcare Commission CSCI - there were no restrictions on its remit.
It said the review was looking to "streamline" the system while ensuring the quality and safety of services was maintained.