Elizabeth Sidwell, in her striped blazer and turquoise scarf, is a petite woman with greying hair and a direct, fixing gaze.

The stare is well honed after years of headship and is employed to great effect as she complains, half-mockingly, about her difficulty in having a copy of The TES delivered to her desk now she is in her new role as schools commissioner within the Department for Education’s buildings in Whitehall.

“I’m used to having The TES coming on a Friday, you see. And I asked: ‘Where is it?’ I was told I could walk upstairs and get it, but I don’t want to do that. I want it here to the Office of the Schools Commissioner; I want it delivered,” she explains.

It is unlikely that Dr Sidwell will be forced to wait much longer before her personal TES is delivered to her door. It is clear she is used to things being done her way.

No doubt, her powers of persuasion were one of the reasons education secretary Michael Gove picked her for her new job, which she started three months ago.

The former chief executive of the Haberdashers’ Aske’s Federation, a cluster of academies in south-east London, was asked by Mr Gove to join the DfE to champion his academy expansion programme.

Chief among her duties is that of “broker”, where Dr Sidwell acts as a type of matchmaker between sponsors - be they well-known providers such as Ark Schools or the Harris Federation, or leading state and independent schools - and struggling schools that the DfE believes need the “academy solution” to turn their fortunes around.

But, as with many arranged marriages, there is often a degree of reluctance from one of the parties. This is when Dr Sidwell’s persuasive powers are of greatest use.

“Invariably, people are afraid of change even if they know they are struggling. So it’s important for us to reassure people and to talk them through (the process),” she says.

To make that process run more smoothly, it is up to Dr Sidwell and her team to find schools and sponsors with as similar characteristics as possible, to ensure the two fit together and can work well with one another in the future.

“You have to talk to the sponsors. Some have areas that they prefer to operate in. For instance, Harris primarily works in south London, although they are expanding into north London. Some may have a CofE affiliation, and you have to look at what their capacity is,” she says. “It is a very careful process.”

On announcing her appointment, the DfE stated that alongside her matchmaking role, Dr Sidwell would be expected to “enthuse” school leaders to go for academy status, making her a cheerleader for the academy programme.

“You can’t force schools to do it (become an academy) and if you did, it wouldn’t work,” she says. “You have to encourage and go out there and say: ‘This is the difference we’ve been able to make’.

“If you have a school where the children aren’t proud of it, the school isn’t full, there is high mobility - things are wrong,” she adds. “Of all the things we’ve tried in education, the academies have had more success than anything else. It’s this independence, so you can tailor the needs to the children you have.”

Dr Sidwell’s claim about academies and their success is debatable. One of the main criticisms of academies has been their use of vocational and non-GCSE “equivalent” qualifications.

As The TES reported last year, less than half of academy GCSE passes were made up of academic qualifications. Indeed, academies were twice as likely as state secondaries to use vocational or equivalent GCSE qualifications.

Similarly, academies were found to be “significantly” more likely than other maintained secondaries with similar intakes to fail the English Baccalaureate.

Regardless of this, the DfE is expecting to see a huge rise in the number of academies by the start of the new school year. With 800 academies already open, the number could well pass the 1,000 mark by September and Dr Sidwell is keen to see more primaries on the list.

Mr Gove has already put forward plans to convert the worst-performing 200 primaries by 2012, and a further 500 are expected to become academies by 2015.

Dr Sidwell believes it is near impossible to sort the secondaries unless the primaries are tackled first. “In some of the most difficult areas, the primaries were feeding out children whom the secondaries couldn’t deal with,” she says, before switching to her own experience as head of a secondary. “We couldn’t deal with them. We weren’t accomplished in teaching reading and writing. For whatever reason, the primaries were not able to future-proof the secondaries as I thought they could.”

It is for this reason that Dr Sidwell would prefer to see more all-through schools being established, where primaries and secondaries unite to make the transition between the two as smooth as possible.

“My own personal preference is that I hope there will be a good number of all-through schools. There is the dip between (primary and secondary), which has been endemic in our education system for some time. Children are re-tested in Year 7 rather than having a nice, seamless trajectory from nursery to university,” she says.

And it will be what she describes as the “big sponsor chains”, the likes of Ark, Harris and Haberdashers’ Aske’s, who will take on the lion’s share of this grand plan. They will start with the worst 200 primaries as they have the resources needed to turn them around.

“We had the 30 key sponsors in recently to tell them the challenge, and they are up for it. Their success rate is considerable and they are very, very important players in closing the gap,” she says.

It becomes clear that it is not just academies that Dr Sidwell is keen to promote, but rather the independence they offer. “It is championing academies or - more - championing independence,” she says.

Independence is practically in her blood. After growing up in South Africa and attending the private Kingsmead girls’ school in Johannesburg, Dr Sidwell moved to the UK in her mid-teens and took her A-levels at the direct-grant Ursuline Convent School in Brentwood, where she described herself as “something of a rebel”.

After university, a career in the independent-school sector followed until she became principal of Hatcham College in 1991, one of the first city technology colleges (CTC) in the country.

In the CTC - a state-funded independent school and a precursor to the academy - Dr Sidwell saw the power of independence to transform underperforming state-maintained schools.

“It was while working at an independent school that I learnt that independence meant being accountable, making sure you were successful; that you had to do it right and that no one was going to cover your back, so you had to,” she says.

“I learned there how to be a good independent-school head, which meant I could take that into the state sector. I really believe that independence is a state of mind; it is a freeing up,” she adds.

Whether Mr Gove’s experiment in state-independent schools works remains to be seen, but in Dr Sidwell he has a determined champion of its transformative powers. And if she has her way, every underperforming school in the country will be going the way of the academy.

CV

1949: Born in Johannesburg, South Africa

Education

1967-69: A-levels at Ursuline Convent School, Brentwood

1969-72: Geography at Queen Mary, University of London

1972-76: Doctorate in geography at the London School of Economics

Employment

1985-91: Deputy head, Forest School, an independent in east London

1991-94: Principal, Haberdashers’ Aske’s Hatcham College

1995-2004: Principal and chief executive, Haberdashers’ Aske’s Hatcham College

2005-11: Chief executive, Haberdashers’ Aske’s Federation

2011 to present: Schools commissioner for England.