The local press spoke of “parents buying up teachers” and warned of a two-tier system where schools in middle-class areas could get teachers by asking parents to dig in their pockets while poor inner-city schools remained chronically understaffed.

English and mathematics teacher Stefan Burde, and Thomas Voskuhl, who teaches Greek and Latin, did their practical training at the Gymnasium Christianeum in Othmarschen, but this September the Hamburg schools authority only agreed to pay for six hours of teaching by Burde and 18 hours by Voskuhl to replace four full-time teachers who left the previous term.

Headteacher Ulf Andersen, in a move unprecedented in Germany, asked parents to bridge the gap - in open contravention of the authority monopoly on employing teachers.

The embarrassed authority finally “found” the funds to pay the two teachers. But by then the principle that only the state is responsible for matching teachers to schools and paying for them was breached.

“I wanted teachers who fitted the ethos and philosophy of the school and they (Mr Burde and Mr Voskuhl) fitted that. Otherwise I would be obliged to take whoever the schools authority offered me, which also might have been no one at all,” said Mr Andersen.

He says a number of headteachers have been coming to him for advice on how to hire and pay for teachers themselves.

The teacher shortfall in Germany’s northern states has become a national scandal as teacher unemployment rises. States struggling to balance budgets say they have no money for new teachers.

Klaus Klemm, researcher in education in Essen, has said that some 30,000 teachers are needed in schools to return to the quality levels of 1980.

The shortfall is serious because Germany has no proper system of supply teaching. In winter when teacher-absences through illnesses are highest, weeks of lessons can be lost. And an ageing teacher population often means extended sick leave.

Parents at one Berlin grammar school complained that the Abitur class last year had no English teaching for four months. Against this backdrop of local authority inaction, parents are refusing to stay silent.

In Griesheim in Hessen the Georg August Zinn comprehensive “borrowed” chemist Doris Neumann-Grimm from neighbouring company Clariant when the local authority failed to come up with an urgently-needed chemistry teacher.

The Berlin authority recently refused to allow parents to pay for a Latin teacher saying only the state had that right and that teachers paid by parents “would be under pressure to give the children of their paymasters good grades”.