The EIS says education should not suffer because of the recession
Teachers' leaders have claimed education funding is under a "very real" threat amid the recession.
The Educational Institute of Scotland (EIS) said students should not have to see the teaching they receive suffer because of the mistakes of others.
The union has launched its "Why Must Our Children Pay campaign".
A government spokesman said local authorities have been given funding levels to allow them to increase education budgets.
EIS general secretary Ronnie Smith said the "bleak financial position was not caused by our schools or colleges or by our young people".
The union said it was organising a protest in Glasgow in March to defend funding for education.
Mr Smith said: "We want to send a strong message to government at every level that our children and young people must not be forced to pay the price for the cavalier behaviour of others that led to this recession.
"The threat to education funding is very real.
He added: "Already over the past year we have seen very significant cuts in education budgets and classroom resources right across the country.
"It is absolutely vital the frontline public services, in particular education, are protected during these difficult economic times."
A Government spokesman said local authorities are given "significant levels of funding allowing them to continue to increase education budgets despite a difficult economic climate".
He said: "Total spending on education has increased over the last two years. However the funding available to the Scottish Government, and therefore to local government, is under severe pressure.
"Difficult local and national decisions have to be made about spending priorities."