Teaching representatives are calling for the education secretary to put a support package in place to help teachers deliver the new Highers next year, before the challenges schools are facing "morph into a crisis".
The EIS teaching union has written to education secretary Michael Russell demanding help for implementing the new Higher similar to that provided for the new National qualifications this year, which included an extra #163;3 million in funding.
The union's general secretary, Larry Flanagan, is also calling for schools to be allowed to decide whether to run the old or the new Higher next year after consulting parents and students.
His call comes in the wake of a letter to directors of education from Bill Maxwell, chair of the Curriculum for Excellence management group, which states that old Highers "should only be available to S6 learners".
It also follows new advice to members from the Association of Directors of Education in Scotland (ADES) - seen exclusively by TESS - urging them to push on with the implementation of the new Highers next year "to avoid curriculum and examination disconnect" - although the advice does add that "local circumstances" may mitigate against the introduction of the new Higher in exceptional circumstances.
In his letter to Michael Russell, Mr Flanagan says: "With regard to the new Higher, I note the letter that Bill Maxwell has issued to schools, which essentially urges schools to ensure that all S5 Higher pupils in 2014-15 be presented for CfE Higher.
"In our view, this decision should be made at a school or departmental level, taking into account the school's own sense of its preparedness and the needs of its pupils."
Earlier this month, TESS revealed that the nationwide launch of the new Highers next year was in doubt after some councils had refused to back their full-scale introduction.
In his letter, Mr Flanagan adds that teachers are becoming increasingly concerned about the lack of clear information regarding the new Higher courses. He also highlights the content of the new exams in some subjects, the lack of resource material to support the learning and teaching process in the classroom, and the demanding workload implications of attempting to prepare for new Higher exams at the same time as implementing new National 1-5 qualifications.
In short, he says, there is "considerable heat in the system". He urges the Scottish government to leave it up to schools to decide if they are ready for the new Higher, and calls for support in its delivery to be introduced "as soon as possible".
Mr Flanagan continues: "We wish to see a suitable support package put in place around the introduction of the CfE Higher, not dissimilar to that offered around National 4 and 5, and for this to happen as soon as possible before the challenges morph into a crisis."
However, in his letter to education directors, Mr Maxwell sets out the expectation that "all schools and centres will adopt the new qualifications in line with the national timetable for implementation in 2014-15".
He adds: "The new Highers are designed specifically to provide smooth progression from National 5. Pupils who are in S5 in 2014-15 will therefore benefit from Highers that are designed to be aligned to the principles of Curriculum for Excellence and in the best interest of the learner.
"The former Higher courses should only be available for S6 learners, although in those cases schools may choose to deliver the new Highers if that is more practical."
The Scottish government responded to Mr Flanagan's comments by saying it was "confident" that schools were preparing for the new Highers next year.
A spokesperson said: "The Scottish government, Education Scotland and the SQA (Scottish Qualifications Authority) will continue to listen to and work with the teaching profession to ensure the very best outcomes for our young people."
We wish to see a suitable support package... before the challenges morph into a crisis.