Even though headteachers are unlikely to be allowed to continue with the old version of Advanced Highers next year, there is little chance of the new qualification being boycotted en masse, education directors have told ministers.

However, concerns about Curriculum for Excellence appear to be growing, with a number of schools going public over their fears that the reform is falling short of its aims.

Last week, trade unions told the Scottish Parliament’s Education and Culture Committee that teachers should be allowed to continue running old Advanced Higher courses when the new version became available in August, just as they were able to choose this year between new and old Highers.

Larry Flanagan, general secretary of the EIS teaching union, said that if they could not, workload pressures would cause many schools to drop Advanced Highers and the qualification would become “marginalised”.

In a letter to the Scottish government, however, education directors’ body ADES played down suggestions that Advanced Higher courses had already been scrapped in many schools. ADES was also “very surprised” at the suggestion that teachers might “boycott” the new qualifications.

The letter states: “Local authorities have not reported that this is likely to happen, and, having been with over half of Scotland’s secondary headteachers last week, again there were no reports of such thinking. We do not therefore understand why such suggestions were made to the committee and indirectly to Scottish parents.”

Advanced Higher courses are being planned “in a manner that ensures individual needs are met, either in the local school or on a collegiate basis across groups of schools, or even colleges and universities,” the ADES letter explains.

It adds that a meeting is being planned “in the near future” between ADES and the EIS to address concerns around the Advanced Higher “in a positive and proactive manner”.

However, schools’ fears over the implementation of CfE appear to be growing, after several headteachers told the education committee that the reform was in danger of doing the very opposite of what it was supposed to achieve.

Delivering both the new Higher and Advanced Higher courses next year would present a “significant challenge” to schools, said David Dempster, headteacher at Edinburgh’s Boroughmuir High School. He insisted that assessment had to be simplified to enable the “creative and dynamic learning” espoused by CfE.

Mr Dempster added: “There is no doubt that the demands of assessment that have shifted to teachers are wholly disproportionate.”

Derrick Hannan, headteacher of Braidhurst High School in Motherwell, North Lanarkshire, told the committee that the absence of external examinations for the National 3 and 4 qualifications was a “total disaster”. More than half the pupils at his school would never sit any exams, with the result that some would feel “a total lack of any sense of self-worth”, he said.

Mr Hannan added that CfE had resulted in a “sea of assessment” for teachers to contend with, but rather than leading to more depth and a greater emphasis on skills, too much and too varied assessment meant “we have lost the very things we set out to achieve”.

David Nicholls, headteacher at Gleniffer High School in Paisley, Renfrewshire, said that preparation for CfE over the past five years had “lacked clarity, direction, leadership and planned or structured support”.

Budget cuts represented the biggest risk to CfE, according to Colin Stewart, headteacher of Hamilton Grammar School in South Lanarkshire. “The scale of these in the next three years is leading some authorities to consider making changes [that would have been] unthinkable in past years,” he says. “In my view there is a real threat to further implementation of CfE.”

Criticism also came from the private sector, with George Watson’s College headteacher Melvyn Roffe stating that pupils at the Edinburgh school now had to take between 50 and 90 assessment exercises in S3 and S4 alone. Similar trends were now emerging at Higher and Advanced Higher level, he added.

New assessment requirements placed “too much emphasis on establishing basic standards rather than enabling pupils to strive for true excellence”, Mr Roffe said.

Education Scotland told the committee that it had carried out 44 school inspections between September and December 2014 and found that schools were continuing to perform well.

“The positive impact of CfE on children’s and young people’s learning experiences and personal attributes, such as confidence and motivation to learn, continues to be a key strength identified in over 90 per cent of inspections,” the organisation said.