Fewer than a third of new teachers have found permanent jobs this year, compared to more than a half in 2008, according to a survey of post- probationers by the General Teaching Council for Scotland (GTCS).
The figures, released this week, also show an increase in new entrants either on supply lists or unable to find teaching work at all.
The trend was described by the Labour Party as evidence of the "casualisation" of the teacher work- force and came as Government statistics showed a decrease in the number of teacher vacancies advertised.
The squeeze was also evident from separate figures showing a decline in the number of probationers being taken on next year by some authorities. The number looking for training places has fallen from 3,478 to 3,217.
Glasgow City Council, Scotland's largest education authority, said it would be offering 146 primary and 52 secondary places to new teachers on the induction scheme; this compares with 167 primary and 139 secondary allocated places last year.
A council spokeswoman said the reduction reflected "the national difficulties with teacher workforce planning due to overall financial pressures and declining pupil rolls".
The GTCS survey - a follow-up on its annual employment survey last October - achieved a response rate of 41.5 per cent compared to 39.4 per cent last year; the October 2009 survey received responses from 48.4 per cent of new teachers.
The last three GTCS April surveys have shown an increase in the number of probationers on supply work, from 12.7 per cent to 19.6 per cent to 26.5 per cent; at the same time, the number gaining permanent posts has declined from 51.3 per cent to 39.5 per cent to 30 per cent.
In the primary sector, the percentage of teachers in permanent posts dropped from 40.3 per cent in April 2008 to 24 per cent this year; in the secondary sector, comparable figures were 74.2 per cent and 48 per cent.
Tony Finn, chief executive of the GTCS, described the trend as "disappointing, if not surprising".
Michael Russell, the Education Secretary, said progress was being made on new teacher employment, adding that the GTCS survey showed 86.4 per cent of new teachers were now in employment or on a supply list - an increase of 13.9 per cent since the start of the school year. "However, I want to see more of our new teachers finding jobs and I have sympathy for those who have, so far, been unable to do so. I am committed to doing what I can to help improve the situation," he said.
"That's why I took the difficult decision to reduce the intake of student teachers and therefore reduce the number of probationers entering the system this summer. This will help free up jobs for newly-qualified teachers still seeking employment."
Ronnie Smith, general secretary of the Educational Institute of Scotland, said it was "a tragedy" that so many newly-qualified teachers were unemployed or under-employed on short-term contracts and called for quick and decisive action from the Government to ensure local authorities employ more teachers.
John Stodter, general secretary of the Association of Directors of Education in Scotland, expressed disappointment in the trend, as the quality of newly-qualified teachers had "probably never been higher".
He added: "It is not surprising that councils, which have reducing budgets and increasing costs, particularly additional employment costs for teachers, for example, new leave entitlement, will tend to employ fewer teachers because this is the biggest single draw on their budgets."
- Government teacher vacancy statistics showed the highest were in the following categories: primary head and depute 1.8 per cent; secondary head and depute 1.4 per cent; home economics 1.3 per cent; additional support needs 1.8 per cent; secondary Gaelic medium 1.6 per cent; and educational psychologists 5.5 per cent.
Leader, page 22.