A German education official has threatened to close Berlin's bilingual Europe schools if English-speaking teachers continue to demand equal pay with their German colleagues.
British-trained teachers are being paid 40 per cent less than their German-trained counterparts because the authorities refuse to recognise them as qualified teachers. German initial training lasts longer - five years.
This breaches European Union rules on the mutual recognition of qualifications. Legal action taken by a Scottish teacher, June McTaggart, has prompted Brussels to issue infringement proceedings against the German government. In July Germany was also told to fall in line on recognition of work experience.
The issue has erupted into a row and the main teachers' union GEW has provided legal insurance for Ms McTaggart.
Dagmar von Loh, the senior education official in charge of the Europe schools summoned one teacher campaigning on behalf of the British teachers and said he would face disciplinary action if he talked to the press or parents about the pay issue. The teacher, Steven Lange, said she threatened to "snuff out" the Europe schools, but she has since denied it.
Mr Lange, an American teacher paid the German rate because he trained in Germany, said: "English, American, Canadian and Irish training is recognised to the point that you can be a class teacher, do anything that the German teachers do: the only difference is the pay."
The row has come at a particularly sensitive time in Berlin, when diplomats are moving their families to the newly re-established capital and will be looking for bilingual schools to educate their children.
The Europe schools were first set up seven years ago, by the Berlin Schools Authority, as a model of European integration. Their intake is split between Germans and speakers of one other European language.
The EU action follows legal action taken by June McTaggart, a founding teacher at Charles Dickens primary and one of 18 native-English-speaking teachers in the Europe schools.
She has lost three legal battles to have her qualifications recognised as equal to the German ones. She is fighting a fourth in the industrial tribunal with GEW's backing.
As a result of her action the Berlin schools authority inserted into its guidelines on teachers' pay separate clauses on the pay of foreign teachers and a different scale specifically for the Europe schools.
She said: "You shouldn't get 40 per cent less for doing the same job. I firmly believe in a united Europe, but if we don't trust each other's qualifications how can we trust each other on other issues?"