The controversial plans to overhaul teachers' pensions have galvanised the profession into taking industrial action, with thousands of schools forced to close in June and more unrest expected in November.
But new fears have emerged that the proposed pension changes are having a wider impact on the school workforce. The annual school census in Wales has revealed a spike in the number of early retirements, and it is claimed that the proposed pension changes are partly to blame.
The figures reveal that premature retirements increased by 13 per cent in Wales in the last academic year - the biggest percentage increase since 200405.
The most recent figures for England have not yet been published. However, the trend for early retirements has mirrored that in Wales, with an overall rise over the past decade and a dip in 200910, raising the fear that England's schools could also be in for a glut of teachers calling it a day.
Teaching unions say a number of factors are contributing to the rise, but agree that planned pension changes are a key cause.
Dr Philip Dixon, director of education union ATL Cymru, said: "I think a lot of teachers have eyed the reforms, done the calculations and thought they might as well go now."
Welsh-medium teaching union UCAC is due to lead its members out on strike on 5 October. General secretary Elaine Edwards said there was a great deal of concern about the pension changes, which would see teachers contributing more and getting less upon retirement.
"We have had teachers in their mid-50s asking questions about the pension changes and saying they want to leave prematurely to avoid them," she said. "We've told them we are negotiating and trying to fight the changes, but some still want to go now."
The Westminster Government accepted recommendations on public-sector reform from Lord Hutton's independent report published in the spring. Teachers currently pay 6.4 per cent of their salary into their pension, but from April 2012 that could increase by up to 2.4 percentage points for the highest-paid.
The Government says the changes are necessary because people are living longer and the cost of teachers' pensions will double to #163;10 billion by 2015. But fears over early retirement follow concerns that asking the highest earners to pay even greater contributions will deter teachers from seeking headships.
Similar fears over pension reforms are affecting teachers across England and Wales, according to Brian Lightman, general secretary of the Association of School and College Leaders.
"A number of people are thinking about leaving early as a result of these changes," he said. "Our advice is there's no reason to go early because it's people earlier in their teaching career who will feel the full force of the reforms."
Decisions over teachers' pensions, pay and conditions are not currently devolved to Wales.
In Westminster, the Department for Education insists there is no evidence to suggest that the increase in early retirements is in response to pension changes.
"These discussions are continuing and no decisions have yet been taken about long-term reform of schemes," a spokesman said. "It is expected that any changes to teachers' pensions would be introduced from 2015. Teachers considering retiring early to avoid those changes would only guarantee themselves a lower pension than if they continue working."
ATL Cymru said the rise in retirements could also indicate how tough teaching is becoming, with more teachers choosing to leave early due to stress, workload issues and bullying.
"We need to tackle those things," Dr Dixon said. "No one should be driven out of the profession if they feel they still have something to offer."
But whether planned pension changes or workload and stress are behind the rise, the very fact that more heads and teachers are seeking to retire prematurely will pose some worrying questions for the governments in Westminster and Cardiff Bay.