The government must use its first “mandate” to prove its “willingness to truly release a tight political grip from the NHS”, Malcolm Grant said.

The independent board will take over full responsibility for the £80bn NHS commissioning budget from April.

The mandate – which the Department of Health will consult on in the summer – will set the service’s funding and describe what it should deliver during 2012-13 and probably several years beyond.

HSJ last week revealed the board was concerned the government would use the mandate to load the NHS with a large number of instructions and process requirements.

Professor Grant told HSJ this week such an approach would “undermine” the government’s own objectives.  He said: “We see the mandate as an early test of the integrity of the new structure and of the government’s willingness to truly release a tight political grip from the NHS.

“My preference is much more for simply expressed and measurable outcomes as opposed to complex inputs and processes.”

He warned against an “inevitable tendency for everybody to wish to insert some reference to every [medical] condition”, and said the board would have to pass on any such requirements “as part of the operating framework for the CCGs”.

He also predicted “a lot of argument” about the outcomes expected from the service.

Once the mandate is set, the government will only be able to give new instructions to the NHS in very restricted circumstances.

Professor Grant said to help protect the board’s independence any “attempt [by the government] to influence any action would need to be done in a publicly visible and accountable way”.

Asked how he would react if the government sought to direct the board – for example, to protect particular hospital services – he said: “We will deal with that when we come to it.” He indicated Andrew Lansley – as the “architect of the reforms” – was unlikely to try to compromise the board.

However, Professor Grant said he did not believe the board’s independence meant the health secretary “stands back entirely [from the NHS]… there will be dialogue”.

He said: “There is still huge political interest in the health of the nation. Setting up the board doesn’t absolve the [government’s] responsibility of providing comprehensive healthcare.”

Separately, NHS Confederation chief executive Mike Farrar this week warned politicians from across government would seek to influence the mandate. He said issues of public concern such as dignity and care, older people’s care and dementia would come to the fore.

Mr Farrar added the mandate would be created by “a political process. We shouldn’t underestimate the impact that will have”.

He said the first mandate should “be realistic” in its objectives, reflecting the fact the commissioning system will be made up of “new organisations [which] will be finding their feet”.