David Worskett, director of NHS Partners Network, said:
"The recent studies confirming the benefits of competition are among the most authoritative ever done. The Government has enough evidence to act - this study is an argument for inertia. If the NHS ignores the benefits of competition on quality patients will suffer and vested interest will continue to dominate the NHS.
"We can see the real positive impacts of competition simply by looking at the much higher levels of patient satisfaction where competition has been introduced.
"Patient choice is a central component of improving any modern healthcare service. All systems need competitive challenge to improve."