A union representing college lecturers has described a revised pay deal from employers as "unacceptable".
College Employers Scotland said the flat cash pay settlement was their "full and final" offer.
But the EIS-Further Education Lecturers' Association (EIS-FELA) said it represented a real terms pay cut.
The union has previously said that industrial action would be escalated to a national strike without an acceptable pay offer.
Some union members are taking part in a "resulting boycott", marking student assessments but not entering the marks in college recording systems.
Lecturers have been offered a £2,000 pay rise in 2022/23 and a further £1,500 in 2023/24, providing an overall £3,500 uplift for all college staff over the two years.
College Employers Scotland said this would proportionately benefit staff on lower pay.
