The education secretary is to set up an expert group to examine how Scotland's new qualifications system could be improved amid the threat of industrial action by teachers.

The group will focus on how to manage ever-increasing teacher workloads and complaints of excess stress caused by ill-received reforms to Scotland's Curriculum for Excellence.

Minister Angela Constance's hand was forced after the Educational Institute of Scotland (EIS), the country's largest teaching union, held an indicative ballot on the possibility of industrial action over the ineffectiveness of the reforms.

Part of the changes to Scotland's educational system included the scrapping of Standard Grades in 2014, replaced by National 4 and 5 Qualifications, while schools were given the option to phase in new Higher exams last year.

However, many teachers complained that the changes were being implemented in an unreasonable timescale, meaning teaching techniques were having to be rapidly overhauled - often to the detriment of pupils' attainment.

Subjects such as English, mathematics and the sciences have been the most adversely affected, while a controversial Higher maths exam had to have its pass mark lowered to 34% last year after a petition signed by pupils, teachers and students complained that the "flawed exam" was far too difficult.

More than 93% of EIS members said they would be willing to take some kind of action over "excessive and unsustainable" workloads.

Ms Constance said the group, to be chaired by learning minister Alasdair Allan, would report back with initial recommendations in March in time for the 2016-17 school year.

She said: "Teachers are at the heart of the success of new Highers and National Qualifications, where record Higher and Advanced Higher results have been achieved.

"We must continue to do all that we can to free up our teachers to teach, lessening workloads through tackling bureaucracy, and minimising stress, for the benefit of all in our education system.

"Following the introduction of the National Qualifications, now is the right time to look in depth at what further improvements can be made in schools."

EIS general secretary Larry Flanagan said: "The overwhelming backing from EIS members in our consultative ballot for industrial action on national qualifications-generated workload clearly indicated that teachers are demanding changes.

"We welcome the fact that an initial report from the group is to be made by the end of March to ensure changes are made for school session 2016/17.

"Whilst this is a challenging timescale, the EIS will enter into constructive engagement with the working group, with the intention of reaching a workable agreement on real and lasting reductions to the bureaucracy, workload and stress associated with the new qualifications."

He said the EIS executive would meet tomorrow to discuss the new group and consider the next steps in light of the recent ballot.

Liam McArthur MSP, education spokesman for the Liberal Democrats, said: "Although I'm pleased this group will examine issues surrounding teacher stress and workload following the introduction of the new National Qualifications, this is at odds with the First Minister's determination to reintroduce national standardised testing.

"Rolling back the years with this return to a Thatcherite policy will only increase workload for teachers as well as stress levels for teachers and pupils alike."