Swansea council is in discussions over whether to allow schools to introduce staff car parking charges. If passed, the fees would be introduced from April 1, and would be decided on a school-by-school basis.
The parking charges would be linked to salary, and the money raised would be kept by the individual schools to bolster their budgets.
But teaching unions have hit out at the proposals, saying they would 'sap morale' in a sector where salaries have not risen in line with inflation.
Elaine Edwards, general secretary of Welsh teacher's union UCAC, said: "It's totally unacceptable that the council would wish to impose parking charges on a public sector workforce that has seen salaries frozen or capped for the last seven years."
"Teachers carry huge loads of books every day, which makes travelling by public transport impracticable. And we're concerned that the imposition of charges will increase the bureaucratic burden on head teachers who might be expected to collect fees and distribute licences."
Head teachers were also less than thrilled with the proposals, which were presented to them at a meeting of Swansea headteachers.
One said: "At the meeting a lot of heads voiced their concerns. I think the general opinion was that it was not a good idea, that it would sap the morale of teachers and that they felt undervalued."
He claimed the local authority said at the meeting that other council workers had to pay for parking. "That does not make it right," he said.
The council responded in a statement. "Due to ongoing austerity the money we receive from Government has again been cut in real terms and we have to find in excess of £20 million in savings next year so face some very difficult decisions.
"As part of our wider budget consultation we asked schools, teachers and their unions for their views about introducing a modest charge for onsite parking bringing them in line with many other council workers.
"The proposal made it clear all money raised would be kept by individual schools and charges would be on a sliding scale dependant on income to protect lower-paid staff. No decision has yet been made."