The NHS Commissioning Board expects to control half of the income for some trusts through its funding of specialised services.

In one of his first public appearances, commissioning board chair Malcolm Grant said responsibility for the NHS was being put into a “variety of hands”.

Clinical commissioning groups were “amongst the most important” of these, he said.

However, Professor Grant added: “Many of the major hospitals in London will receive well over 30, if not over 50, per cent of their revenues from the commissioning of specialist services through the board.

“So the board has [through this and its control of primary care commissioning] some very powerful financial means in order to secure the outcomes we all wish for in the system.

“But beyond that it’s over to you.”

He was speaking at a meeting of NHS Clinical Commissioners, the new body launched by the National Association of Primary Care, NHS Alliance and the NHS Confederation this morning.

Professor Grant also said the NHS Commissioning Board’s mandate from the government should be short and simple enough to be published in the Sun newspaper.

“One of my concerns is there may be a tendency for the mandate to accumulate a great deal of material as it proceeds through the passages Whitehall,” he said.

“I hope we can work with you to try to ensure we have a mandate that is simple and clear… The more material ends up in the mandate the more obscure is the primary message of what it is we need to achieve. What we must resist is any pressure to have every clinical condition described in the mandate, because I fear that will lead quite rapidly to obfuscation and confusion.”

Professor Grant said he expected there would be around 220 CCGs in April 2013.

He also stressed the importance of good use of data and informatics. Professor Grant said he suspected that the best-performing CCGs would be the ones with the best primary care information systems. The ability of CCGs to assess and challenge variation between GPs was “unique”, Professor Grant said.