A considerable amount of work still needs to be done to make sure schools are ready for new exams being brought in from next year, union leaders have warned.
A survey of teachers by the Educational Institute of Scotland (EIS) union found more than half were either "barely confident" or "not confident at all" over the introduction of the National 4 and 5 qualifications.
The exams are being brought in as part of Curriculum for Excellence (CfE) teaching reforms and will replace the current Standard Grade and Intermediate qualifications from 2013-14. With the first pupils due to sit the new exams in 2014, teachers will start preparing youngsters for them later this year.
EIS general secretary Larry Flanagan said: "The fact that around half of classroom teachers are still expressing a lack of confidence indicates there remains a considerable amount of work to be done to ensure all schools are ready to deliver courses leading to the new examinations from this year. We cannot afford for even a small percentage of teachers to be unprepared as that would mean their pupils would be disadvantaged."
Last year the Scottish Government announced extra funding of £3.5 million for secondary schools as part of a package of measures to help them prepare for the introduction of the new exams.
In the EIS survey, just 3.3% of teachers said they were "fully confident" their department would be able to deliver the National qualifications on time, with 7.7% "very confident" and 34.2% "confident". But 43.4% said they were "barely confident" their department could deliver in 2013-14, with 11.4% "not confident at all".
Teachers expressed concerns about the information and support schools had been given ahead of the change. A total of 63.9% described the support from both the national body Education Scotland and the Scottish Qualifications Authority (SQA) exams body as "unsatisfactory".
An EIS member complained: "Teachers are bearing the burden of implementation on top of their daily job. Resources allocated to implementation are completely inadequate." Another said the changes "should have been postponed as the general feeling from teachers is that we are floundering in the dark and we are all concerned that it is the poor pupils that will suffer, along with the stress that this has put onto an already stressful occupation".
Minister for learning Alasdair Allan praised the country's "inspiring teachers" who were "delivering a modern education for their pupils" and promised the Scottish Government, together with bodies such as Education Scotland and the SQA would "continue to do all we can to encourage and support these efforts, with all support materials and events being delivered on time".
Dr Gill Stewart, SQA director of qualifications, said: "We understand that teachers need a full picture of how the new national qualifications will work and SQA is committed to delivering that as quickly and comprehensively as possible."