A new teaching union aims to provide a home for disaffected members of the Educational Institute of Scotland.
The Scottish Primary Teachers' Association, which was officially formed this week, is a direct response to EIS backing for the contentious national two-year deal on pay and conditions.
Convener Brenda Bleackley, a full-time additional support needs teacher and former EIS member, said: "I could not remain a member because I do not condone their actions and advice over the recent Cosla deal.
"In truth, I do not trust them to represent the needs of teachers. There is no need to engage in mudslinging, when their actions speak louder than anything I could say.
Ms Bleackley was more recently a member of the NASUWT, which has far fewer members in Scotland than the EIS but is a major force in England; she believes a specifically Scottish union will better serve primary teachers.
"We are hearing from more teachers each day," said Ms Bleackley. "To date we have teachers in each local authority indicating their interest and some joining already."
Among potential members' biggest concerns have been: the pay deal's impact on supply teachers; changes to pensions; and a sense that the McCormac report will recommend further erosion of teachers' pay and conditions.
Online surveys have shown that greater numbers of teachers with permanent contracts want to join than supply teachers. Most have found the SPTA via social networking sites, but recruitment posters will soon be sent to all primary schools and a website is under development. The union will have elected officials and, eventually, headquarters, Ms Bleakley said.
EIS general secretary Ronnie Smith said: "The effective representation of teachers' interests would best come from a single, unified organisation that speaks for all.
"Splintering into small, factional groups, be it by sector or grade of post, serves only to divide teachers and weakens their representation on the issues that matter.
"Fragmentation of teacher representation plays into the hands of management and increases the risk of targeted attacks on vulnerable groups within the teaching profession."