Margaret Tumber, 52, chair of the Association of Language Learning's German committee since the association's foundation, is leaving her post as head of modern languages at Alec Hunter school in Essex because the new policy goes against everything she has worked for. She fears it signals the start of a widespread trend.
Ms Tumber, with more than 30 years' experience teaching German and French, says: "The two platforms that matter to me, that no matter what their ability every body should do a foreign language and that there should be diversification of first foreign languages, have both been taken away. I personally can no longer stay."
Trevor Averre-Beeson, deputy headteacher at Alec Hunter, says the switch in Year 7 will provide pupils with continuity and ultimately more choice. He says: "It's a fact that primary schools locally all run French classes but not German, so children will come to the school without a foundation in German. We want to support continuity. However, the intention is that they will be given the opportunity to diversify in Years 8 and 9, as children with the aptitude for languages will have the opportunity to take German and possibly Spanish.
"In one sense at the moment we offer less choice, because pupils have to do either French or German until Year 10, where they have the option to take a second language."
Margaret Tumber fears that, at a time when budgets are being squeezed and schools are understandably anxious to get the best results they can by capitalising on the headstart in French provided by primary courses, diversification will fall by the wayside in many more schools.
"I only have anecdotal evidence so far, but I hear there are many places where diversification seems not to be continuing and German is being pushed higher up the school. If the child begins only in Year 8, the standard reached at the end of key stage 4 will not be as high as if they began in Year 7.
"The knock-on effect is that people will want to go on with the language they started in Year 7 and we will end up with fewer doing German and fewer teachers to teach it."
She has heard of one student teacher who as told they would have no chance of getting a job because their languages was German and they were not able to offer French.
"French is becoming dominant again. It's not what we expected when diversification got off the ground. We had high hopes that other languages would go from strength to strength. We are worried now that this is not happening and we are slipping back."
Ms Tumber is standing for re-election as chair of the German committee and is aiming to maintain an active role in education consultancy and training.