It sounded promising. Two years ago the Government announced that every school was to get a “critical friend”, or school improvement partner (SIP), and optimists believed they might be a counterbalance to Ofsted.

Now the concept of the SIP has been included within the new education and inspections Bill as part of each local authority’s intervention strategy.

As a result the SIP idea is looking increasingly critical and less friendly. It’s time for a rethink.

There are three criteria for a successful critical friend: lschools must feel free to choose their own; lhe or she must be part of a trusted but challenging relationship; lthe focus of his or her work must be on school improvement and not be constrained by targets and pre-determined agendas.

How, in practice, does the SIP model match these criteria?

The process has all the hallmarks of bureaucracy, and the jargon to match.

The Department for Education and Skills licenses the National Strategies (responsible for literacy and numeracy) and the National College for School Leadership to accredit and train SIPs. The new education and inspections Bill, currently going through Parliament, requires local authorities to employ and deploy SIPs. Although schools will be consulted on the allocation of their SIPs, the final decision rests with the local authority. And the “single conversation” (supposed to ensure the process works smoothly) means that one person, the SIP, will report the school’s strengths and weaknesses to the local authority.

Against this convoluted criteria, one thing is clear. The SIP cannot be a critical friend. Critical, maybe, but no friend.

Yet, the evidence is that school leaders need to know they can call on friendly advice. Being a headteacher can be the loneliest job in education.

The original appraisal scheme for headteachers, in the early 1990s, enabled heads to provide advice to their colleagues without prejudice and on the basis of trust; in short, to act as genuine mentors.

No doubt those employed as SIPs will act professionally and, of course, the National Union of Teachers is issuing practical advice for both leaders and SIPs. Nevertheless, the SIP concept is essentially adversarial. It militates against the establishment of trust and friendship.

SIPs will inevitably see themselves as primarily accountable to the local authority and not to the school.

The sharpened intervention powers contained in the Bill, giving schools causing concern just 15 days to make improvements spelled out in notices issued by local authorities, will inevitably mean that councils will rely on SIPs to provide them with the information they need to exercise their powers. SIPs will be under enormous pressure to act as quasi-Ofsted inspectors conducting preliminary school inspections.

A national database, constituted from SIP-provided information, on the competency of headteachers could be developed without the protections and independent appeal system built into Ofsted inspections.

In this situation, headteachers will find it very hard not to see SIPs as yet another externally imposed accountability measure rather than as a source of support.

Existing local authority services are also likely to come under pressure.

Effective local authorities target their services to schools that need them most while fostering networks of good practice and knowledge across schools. The idea of a single person with Olympian qualities sufficient to substitute for the rich, specialist range of services which local authorities make available to schools, is absurd. It is a one-size-fits-all approach to school improvement which sits very oddly with the idea of tailored and personalised learning for young people.

The danger is that local authorities will be constrained to cut back on their existing services to pay for and provide a SIP for every school.

The Local Government Association needs to think twice before embracing the role ascribed to it by the Bill. As NUT general secretary, Steve Sinnott, said at our annual conference, local authorities run the danger of being seen as Ofsted’s Territorial Army.

The new local authority intervention powers combined with SIPs could encourage schools to support any attempts by a future government to remove local authority education powers altogether.

There is a model of support which could still be constructed. All headteachers should be entitled to peer mentors who can genuinely act as critical friends providing confidential support.

Local authorities should be given the freedom to provide, and not just commission, a range of improvement services including advisory services working within schools which have problems.

Above all, local authorities should be encouraged to provide services and opportunities to network professionally.

No doubt, the DfES will point to the positive feeback secondary schools gave to the SIP pilot. But this pilot and the Consultant Leadership Programme rested on the voluntary involvement of headteachers. A national, compulsory roll-out, combined with new powers for local authority intervention, is a very different beast.

John Bangs is Head of Education and Equal Opportunities at the NUT