Mike Tomlinson, former chief inspector of schools, could be described as Britain's top consultant, with a post-retirement portfolio that covers public and private sectors, and national and local government.
Since he left Ofsted two years ago, Mr Tomlinson's most high-profile job has been leader of the Government's task force on 14-19 reform. He chairs the not-for-profit learning trust that runs state education in the London borough of Hackney, and the UK advisory board of Gems, a company planning to become the biggest and "most accessible" provider of private education in the UK, advocating lower fees. Gems is also planning to sponsor two city academies.
Despite his busy schedule and wide range of employers, Mr Tomlinson does not see himself as a consultant. He has never advertised his services, he points out. "My wife and I could live on our pension, as many people do.
Some people who go into consultancy see it as the next phase of their careers. I don't. If nobody paid me, it wouldn't make a jot of difference."
Like others employed on a freelance basis for their expertise, he believes a good track record helps. And he believes all consultants, including those doing similar work on a less elevated plane, have to stop at some point. Although his work in Hackney has kept him in touch, he says everyone's expertise becomes less relevant after a few years. He does not plan to continue working indefinitely, he says, though he is reticent about putting a date on the completion of his retirement.
"If I didn't top up my skills, within three years it would be reasonable for a headteacher or deputy to say, 'Hang on, when did you last do this?'"
Mr Tomlinson agrees with Education Secretary Charles Clarke that the recent explosion in the number of consultants has led to a loss of focus. "There are lots of offers around, some of them in very glossy booklets. We have to be careful that what we are buying from external bodies - and internal ones - is of high quality and addresses what we need head on."
He disputes, though, the NUT's assertion that poor-quality advisers were more likely to be spotted and eliminated in the days when they were rooted firmly in the public sector.
"External consultants and companies are equally accountable with public-sector ones. A contract with the council can be cancelled if they don't provide quality or value for money. They can be called to account at a council meeting, just as an internal department can be."
He recognises, though, the potential conflict of interest when a consultant works in the public and private sectors. What would he do, for instance, if Gems set up a low-fees private school competing with Hackney's comprehensives?
Mr Tomlinson is emphatic: his role at the learning trust would have to take precedence. "I am committed to the long term in Hackney. I have made it clear that if any bodies I am involved with became involved in Hackney, there would be a conflict of interest. I couldn't sustain my position in both. But it would have to be a real conflict, and I don't envisage that."