I will break opposition habits and praise the Government, before offering some critical comment. It would have been easy for a new government to have ditched the ACfE. The SNP didn’t, and they were right not to.

The new curriculum is central to the ambitions we should have for Scottish education. It was never just about the curriculum itself; it was also about what else it would do to reform vital aspects of our system.

One key dimension is about strengthening teaching, by giving teachers back trust. In so doing, we could move teaching further from the impoverished circumstances it found itself in at the end of the last century, when it was undervalued and awaiting the next instruction from the centre, to re-establish it with more responsibility and control.

Another dimension of ACfE is its ability to challenge the orthodoxy and influence exerted by our exams system, the determinant of what is taught in schools. Exams are important, but we have a system which exerts an undue influence on schools, significantly determining what is learned, how resources are allocated, the structure of classes and the focus of school life. Sport, music and the wider arts have been marginalised.

Our exams must assess what it is that pupils learn, not teach what is about to be assessed, only because it is about to be assessed. Our teachers and pupils need more freedom to choose within a national framework. It is ACfE which will drive these changes.

The latest document, Building the Curriculum 3, is good, even if it is disappointingly light on pushing vocational learning hard within the new framework. Yet there is growing disillusionment about the implementation of the changes.

Many appear unclear about the vision and purpose of ACfE and what more professional freedom means and brings. Worse, there are concerns about the preparedness of teachers, with too many unsure about what is expected of them. There seems equal measure of doubt that teachers will be given extra freedoms, and fear they will be criticised for using it.

There has been talk of a loss of momentum, a lost year of potential progress. Exhorting people to do more and to take ownership is a necessary part of the equation, but it is not all that is needed from ministers.

At the heart of the ability to deliver are teachers, yet there is little sign of the massive investment in them that was needed. One reason we planned to build on already increased education spending, was for just that purpose. Ministers would be well advised to grasp that expensive nettle quickly. The alternative may be to lapse into the prescriptive guidance which some teachers seem to crave - while also asking to be left alone!

ACfE is the best chance there is to escape rigid guidance, and investing adequately in teachers’ preparation for their role is vital.

Teachers and schools also need to be assured politicians will back them in breaking new ground, in using their new freedoms professionally. Offering new options and approaches must not result in heightened risk of criticism. That is a challenge HMIE is perfectly capable of meeting, but the ground rules need to become explicit.

Having given away the levers she had, it is not clear Fiona Hyslop can ensure local authorities will use the resources given to them for ACfE on its development, but she must insist on that. We cannot afford to have a postcode lottery in the delivery phase.

Most of all, ministers need to drive this process and adopt a hands-on approach. If they fail, it will be a colossal lost opportunity for Scotland. There remains much to do to ensure success.

Peter Peacock is the former education minister.