Assuming the new Education Secretary Ruth Kelly pursues the policies left by her predecessor, secondary headteachers face the harsh pressure of more intense competition between schools in the years to come.

Having complained about traditional forms of accountability to elected local authorities and demanded what John Dunford, general secretary of the Secondary Heads Association, calls “new freedoms” for their schools, heads must now endure the inevitable consequence - a robust internal market separating the “winners” from the “losers”.

Do enough school leaders possess the necessary entrepreneurial skills to thrive in this new environment? The Government’s plans for new academies and more schools with foundation status, will make local competition for high-achieving pupils and inspirational teachers much stiffer after the next general election. Aspects of the New Relationship with Schools project, announced last January to further loosen schools’ links with LEAs, will also increase competition.

Effective marketing, strong financial management, and excellent leadership skills will be required, as competition shakes up schools. Headteachers will find they do not automatically win the deference traditionally accorded to them by staff and have to delegate more management decisions.

The signals of change have been clear for some time.

There is now a respectable intellectual and political case for promoting competition between schools as a means of encouraging rapid innovation and improvement. The guru of internal market theory in public services, Professor Julian Le Grand of the London School of Economics, was appointed as a Downing Street policy adviser early in 2004, and his writings lay out the theoretical advantages.

Meanwhile, recent articles on “active citizenship”, by Labour’s chief election strategist Alan Milburn and others, talk of giving everyone a choice of schools and hospitals, spreading choice from those who can afford to pay to those who cannot. While these ideas remain controversial - for example, the claim that more consumer choice strengthens local community involvement is arguable - the direction of policy is clear.

However, hard evidence from abroad also highlights the predictable downsides of allowing parents to choose schools. Since the late 1980s in New Zealand, schools have competed openly for students and catchment areas do not exist.

The result, say US researchers Edward Fiske and Helen Ladd, is that New Zealand’s schools have become more segregated by class and race. Their report When schools compete, outlines how the “middle-class” majority of European descent have learned to work the new system more skilfully, with unsuccessful schools becoming repositories for poorer and harder-to-educate children. Wider social objectives have been neglected by market forces and no government “safety nets” have materialised.

The internal market model also raises practical issues for those committed to system-wide educational reform. Inter-school partnerships will be essential if the vital 14-to-19 agenda - so powerfully outlined by former chief inspector Mike Tomlinson and others - is to see the light of day without considerable local duplication of courses that would result from a market approach.

Collaboration will also be important for the new Children Act, enabling schools to adjust faster to a new, cross-agency, world of integrated children’s services, and for other government objectives such as ensuring a smoother transition between primary and secondary schools.

However, experience from the UK and abroad suggests that collaboration will not be achieved solely by school leaders working together. Those kinds of networks tend to be short-lived, or dominated by one “model” local school, since they lack the key ingredient of skilled, and objective, external facilitation and the wider knowledge of best practice that agencies like local education authorities can provide. The aim has to be to construct long-term collaborative networks, carefully linked to a wider education system, capable of meeting the inevitable challenges of further change to come.

There is also a more immediate task. Overall secondary results are coloured by the problem of “coasting” schools, often located in rural and semi-rural areas where competition simply cannot generate the pressures now visible in London. These schools need effective support from professional advisers and consultants, trained to identify accurately areas of weakness and trusted to help them apply practical remedies. The key to this is often strengthening internal management, rather than short-term quick fixes. We will certainly need highly professional educational leadership in the tougher, post-general election, environment, both from within and outside schools.

We will also need an effective and pro-active “middle tier” agency between central government and competing local schools - a modern version of the traditional LEA- to ensure that collaboration happens where necesary and to protect the interests of all local children. Such an agency will also sustain the collective moral purpose which underpins the commitment and contribution of education professionals.

John Chowcat is general secretary of the National Association of Educational Inspectors, Advisers and Consultants