Even more teachers are likely to be hurriedly swept into post over the next few months to meet the cuts in teaching hours required by the post-McCrone national agreement, The TESS has learned.
Ministers are believed to have unearthed more than pound;10 million extra to give councils the flexibility they need to recruit yet more staff in primary and secondary sectors.
All councils were poised to meet the August deadline for limiting teaching hours to no more than 22.5 a week but, as the Headteachers' Association of Scotland pointedly revealed earlier this week, only at the cost of biting cuts in school budgets and excessive pressure on senior management.
That strain is now likely to be eased after an analysis by the local authorities and it appears likely that the Scottish Executive will release several million pounds extra to offset the costs of employing more teachers - provided they are available.
Ministers have already injected pound;62m over 2006 and 2007 to employ more teachers to help meet class-contact reductions and move towards the targets on cutting class sizes by next year. But it appears they have conceded the argument for even more cash.
An executive spokeswoman said reducing teachers' classroom hours to give them more time for lesson preparation was a key part of the agreement "which every council in Scotland signed up to". Ministers were fully committed to meeting the staffing target of 53,000 teachers by next year.
A parallel HAS survey, based on evidence submitted by members of its council in 26 authorities, revealed that only three authorities - Glasgow, Aberdeen and the Western Isles - have appointed enough staff to ensure the cut in teaching hours goes smoothly in secondaries.
Bill McGregor, general secretary, said his association was not in the business of attributing blame, but there was clearly a funding mismatch between the executive and local authorities and discrepancies in how councils spent money targeted at education - "assuming they got it in the first place".
Mr McGregor said: "Here are the facts. Ministers are saying that there are more teachers and more money in the system but the evidence is that this is not the case, with three exceptions."
One of the most "iniquitous" features was the clawback of school money by councils. Some secondaries would have to repay up to pound;50,000.
Schools in most authorities are reporting budget cuts and several are being forced to hand back cash to their council in the guise of "historical management savings, efficiency target savings, procurement savings, cash target savings, slippage targets, management savings".
The HAS states: "The inevitable conclusion is that the majority of local authorities are imposing cuts at the same time as real staff reductions when the need is for increased staffing and resourcing."
The heads say that "the inevitable conclusion" of the funding shortfall - if it persists - is the use of senior school managers for extra teaching; increasing class sizes; cuts in absence cover; a squeeze on the curriculum leading to cuts in Advanced Higher and Intermediate courses; and more stress on class teachers.
The improvement agenda could be at risk, it warns.
Ewan Aitken, education spokesman for the local authorities, has challenged the association's approach and warned it about its future role advising the employers.
"It's really important we have headteachers at the table as opposed to the press conference, and I expect them to act responsibly as advisers," he cautioned bluntly.