Since it was introduced in Wales last December, the secondary school banding system has been almost universally opposed. The return to national rankings has been described as "blunt and crude" by opponents, including the teaching unions.
Headteachers are now calling for the system to be overhauled by replacing the single grade that schools receive with a "report card" that grades different areas of performance. Heads believe that judging schools on a wide range of elements will more fairly reflect their strengths and weaknesses and will be more useful to parents.
Anna Brychan, director of heads' union NAHT Cymru, said she welcomed a "forensic" check of school performance but that the current banding system failed to provide it.
"The uniform single banding number is a blunt instrument that does not give the necessary precision for us to be sure that scant public resources are being targeted at the parts of the school system where they will have the most positive impact," she said. "The fact that some schools have had aspects of their work judged as excellent by Estyn but still have had a low banding judgement overall illustrates a problem that has left many parents puzzled.
"Our report card would address that. Parents understand the approach in the context of their own child; it is a little unfair to assume that they wouldn't in the context of a whole school."
The irony of the current system is that it takes into account a much wider range of performance and data measures than league tables used to, but boils the information down to a single grade. Schools are then placed in one of five performance bands, with the highest performing put in band 1 and the lowest in band 5.
The NAHT raised the idea of introducing report cards at its annual conference in Harrogate last weekend. The Association of School and College Leaders has signalled its support for the proposal.
But classroom unions have not shown similar support. Rex Phillips, Wales organiser for teaching union NASUWT, said he would have "very serious" concerns about the approach, which he said was an attempt to shift the responsibility for standards from headteachers to individual school departments.
The union for Welsh-speaking teachers, UCAC, agrees with the NAHT's analysis of the problems of banding, but its members have called for the government to reconsider the system. Speaking at UCAC's annual conference at the end of April, Jeffrey Connick, assistant head at Ysgol Gyfun Gwyr in Swansea, accused the banding methodology of being flawed and said the system had an "uncomfortable air of competition".
But despite the opposition, the government appears to be sticking to its guns, with a spokesman insisting that there would be no "rethinking" of the system.
"Banding was a manifesto commitment of this government and it is being implemented," the spokesman said. "It is at the heart of our school improvement agenda and will give us and parents a clear picture of how secondary schools in Wales are performing."
The government insists that banding is not about "labelling, naming or shaming", or creating a crude league table, and claims it is a "far more sophisticated approach" than ranking systems used elsewhere in the UK.
Lessons from the US
The idea of a report card for schools is nothing new. Indeed, it was a central education policy of the last Labour government in Westminster.
Back in 2008, the then Department for Children, Schools and Families was inspired by a visit to New York to introduce a report card in England as a fairer alternative to league tables.
But, like banding in Wales, that system relied on an overall grade. In New York the scheme had to be revised in 2009, just two years after implementation, after 97 per cent of the city's elementary and middle schools gained A or B grades.
The coalition government quietly dropped the plans in September 2010.