Sir David Nicholson has defended himself before MPs and said he is “determined” to remain in post as the government’s NHS reforms are introduced.

The NHS chief executive appeared before the Commons health committee on Tuesday.

He was questioned intensely over his management while he was chief executive of two West Midlands strategic health authorities overseeing Mid Staffordshire Trust – later foundation trust – and about the culture of the NHS.

His appearance follows persistent calls for him to lose his job, from campaigners, newspapers and health professionals, since the report of the Mid Staffordshire Foundation Trust public inquiry.

Sir David, while accepting there had been failures in the NHS in the past which led to a lack of focus on patients, said: “I absolutely get the changes that [now] need to happen.

“Given my commitment to the [NHS] constitution, my commitment to patients, and transparency, I think I’m the right person to take it [the changes] forward.”

Since the Mid Staffordshire scandal Sir David said he had “redoubled” his efforts to improve quality of services in the NHS.

He highlighted the risk to the service in coming weeks as the NHS makes the transition to a new commissioning system, under the governments reforms. Primary care trusts and strategic health authorities will be abolished at the end of this month, while CCGs and the NHS Commissioning Board, of which Sir David is chief executive, will take on its full powers.

Sir David, appearing to highlight this situation to justify the importance of him staying in post, said the changes were “fraught with risk”.

He said: “In the next few days we will abolish over 160 organisations and we will set up another 211 local organisations and a whole myriad of national ones. It is at maximum risk over the next few days.

“I said two years ago that I would take the responsibility of leading the NHS through this enormously complex set of changes. I promised I would see that through and I’m absolutely determined to do that.”

Sir David also told the committee he did not come across hospital standardises mortality ratios during his time in the West Midlands, and said they were “not freely available” to SHAs or the NHS during that period.

Sir Brian Jarman, who led the development of hospital standardised mortality ratios, subsequently pointed out that the Dr Foster first published the figures in its Hospital Guide in 2001, and that the information was available to the SHAs online from 2004.

Meanwhile, Sir David said it was “completely and utterly unacceptable” to gag NHS staff wanting to speak up about patient safety concerns. He said: “I would not sanction anything of that sort.”

Pressed by the committee on whistleblowing, he pledged that individuals’ would “have the protection of the department and myself to speak out on patient safety issues”.

He said those who “believe the clauses they have stop them from speaking out about patient safety then they can write to me”.

Sir David also repeated his apology to the families affected by deaths and poor care at Mid Staffordshire and accepted he was wrong not to have met with them, including the Cure the NHS group, in 2009.

Sarah Wollaston, a GP and Conservative Commons health committee member, said after Sir David’s appearance - in which she questioned him about his role - that he should see through the NHS transition, and then resign as NHS Commissioning Board chief executive soon after.

She told HSJ she believed it was “no coincidence” that Sir David had declined to blame any particular ministers for the structural reorganisations which he said had distracted NHS managers from focusing on patients under Labour, as four former Labour health secretaries publicly backed him in the Independent that morning.

Sir David’s supporters were “closing ranks” around him, she said.

Dr Wollaston said that in citing structural change as a key factor in the Mid Staffordshire scandal, Sir David was sending out a “warning” not to remove him amid the government’s commissioning reforms.

Mike Birtwistle, managing director of political consultancy MHP Health Mandate, said he “wasn’t sure the select committee session has changed anything”. The committee failed to “shed new light” on the Francis inquiry.

“It was uncomfortable and would hardly make Sir David feel good about himself, or his political masters feel good about him,” he said.

“But it didn’t move the story on or create a compelling new reason for him to resign.”

By David Williams