Ministers have announced a rethink on their languages strategy

The schools minister sent out the instruction in January amid concern at the decline of language lessons - which the government had made optional.

But a survey of 1,086 schools finds it was obeyed in only 17% of those where not all pupils already took a language.

The government has now ordered a review of the whole subject.

It has asked Lord Dearing to investigate and deliver an interim report before Christmas.

Less than 50%

The survey has been carried out annually since 2002 by the National Centre for Languages, Cilt.

It invited 1,576 state schools and 424 independent schools to take part this year. It said 54% responded.

Languages are too important to simply be allowed to sink or swim in a competitive curriculum Linda Parker Association for Language Learning

Among the findings: a majority of state schools now have less than 50% of pupils studying a language in Key Stage 4 (the GCSE years).

In 29% of them, less than a quarter of students continue with a language after age 14.

The survey also identified a growing tendency for fee-charging schools to drop languages.

Last year, 78% had all their pupils studying a language. This year it was down to 56%.

As for the instruction to set a target, one language teacher responding to the survey said the reply from the senior leadership team in their school had been "that this was the same government that had made languages optional at 14 so, no, they weren't going to take it seriously".

Among other trends, German is said to be "decreasing rapidly", with many schools reporting that it has been phased out.

But lesser-taught languages are improving in popularity.

The survey suggests 4% of state schools now offer Chinese, Russian or Japanese.

'Too important'

Separate research on the further education sector indicated that students who studied vocational courses such as travel and tourism or business were unlikely to be offered the chance to study a language.

Fewer than half of UK colleges offered languages with vocational courses and this proportion was declining, Cilt said.

The director of the Association for Language Learning, Linda Parker, said: "Languages are too important to simply be allowed to sink or swim in a competitive curriculum.

"We know Lord Dearing is looking at incentives for both schools and students to improve take up, and these surveys show just how important that is."

A spokesman for the Department for Education and Skills said: "We want to see what more can be done to encourage 14-16 year olds to study GCSE or other language courses.

"That is why the Education Secretary, Alan Johnson, recently asked Lord Ron Dearing to carry out a review of languages policy.

"We are already investing heavily in the National Languages Strategy and have introduced languages at primary schools to encourage more children to learn a foreign language."