School budgets in Northern Ireland will be robbed of more than £87 million because of Westminster cuts, a teaching union said today.
Principals' spending plans will be "shot to pieces" with teachers and classroom assistants facing inevitable redundancies, the Irish National Teachers' Organisation (INTO) added.
Until now, Northern Ireland government departments could carry money over to the next financial year. But Treasury rules have changed without notice.
In total, Northern Ireland is losing £300 million of funds.
Frank Bunting, northern secretary for the INTO, said: "It's as plain as a pike staff that teacher and classroom assistant redundancies are an inevitable consequence to this shocking example of daylight robbery and shifting of goalposts.
"INTO welcomes the efforts being made to protect frontline services by the minister but the consequences of this devastating cut are incalculable. Many school budgets will be shot to pieces."
Schools have been setting aside unspent parts of their budget and saving it towards purchases like new buses. Now that £87.2 million has been taken off them.
Finance Minister Sammy Wilson was interviewed about the matter.
"This is not about departments being careless about spending. It was planned, money was allowed to be carried over," he said.
"The Treasury always allowed this. Then, without notice, a decision was made to take it away. It was really just swiping money which had built up in Northern Ireland to sort out a hole in their finances."
New school builds will be a casualty of the push to save millions of pounds.
To avoid large-scale job losses, Education Minister Caitriona Ruane intends to shift £41 million from the school building "capital" budget to pay instead for services and staffing.
Meanwhile, up to 4,000 jobs in the health service could be lost over four years as a result of the budget cuts, health officials have warned.
To provide an efficient service, officials said they needed £5.4 billion by 2015 - instead they are to get £4.6 billion - a shortfall of £800 million.
The elderly and the most vulnerable will be worst hit by stringent cuts.