The exam treadmill threatens to trip up more teachers than ever thanks to last-minute changes and a lack of clarity, according to the country’s biggest education union.

Last-minute changes to deadlines for national qualifications by Scotland’s exam body will see many teachers having to shoehorn five months work into four. And the government’s failure to make “a clear decision” about whether unit assessments are to continue to be available at National 5 level this year risks leading to another year of “excessive workload and over-assessment”, according to the EIS.

The Scottish government scrapped unit assessments in September 2016 in a bid to tackle teacher workload, but then reneged on that decision on “an interim basis” and “in exceptional circumstances” six months later after realising that pupils could leave S4 with no qualifications.

However, far from being used only in exceptional circumstances, around a tenth of those presented for N5 exams last year went through unit assessments.

Even if the controversial assessments remain, the Scottish Qualifications Authority has made a last-minute decision - revealed to schools in a letter last week - to bring forward the deadline for changes to N5 unit assessment entries from the end of March to the end of February.

Larry Flanagan, EIS general secretary, called on the SQA to stop making changes to its processes midway through the school year.

“To make changes to the dates for unit entry at the end of October creates additional pressure on schools.

“Teachers now have four months to find four weeks of teaching time, given that if you have finished the units, you have essentially finished teaching the course.”

An SQA spokesman said the deadline for changes to N5 unit assessment entries had been brought forward due to “a significant volume of late submissions” last school year.