A health minister who left her job in the reshuffle has said she resigned because Downing Street advisers meddled in the affairs of the NHS appointments commission and told her not to express views.

Jane Kennedy, who is largely seen as a Blairite, quit over her inability to block the appointment of Sir David Henshaw as chair of the North West Strategic Health Authority. Sir David, the former chief executive of Liverpool city council, was appointed last month to the part-time post.

"It was made clear to me that as a minister I had absolutely no influence at all, and my opinion should not even be expressed, on the appointment," she said. "That view was put to me by a special adviser in Number 10, who has open access to the chair of the appointments commission and thinks this a really good appointment. So I was being told the appointments commission, rightly so, is independent of political influence, but then the penny dropped that only certain political influence gets through."

Sir David, who fell out with the Liberal Democrats on the council, was "the wrong person to run the NHS", she said.