The teaching profession normally defends itself against accusations that A-levels are getting easier as more students achieve top grades.

But a modern foreign languages expert has broken ranks over improved results in his discipline.

Rhys Williams, pro-vice-chancellor and professor of German at Swansea University, said a rise in the number of A grades in Spanish, French and German could be due to more lenient marking.

“The message has gone out that languages are more difficult - I think these results are probably an attempt by examining boards to correct that perception,” said Rhys Williams, who believes an A grade in the subject is no longer a signal of grammatical correctness.

“We have altered our teaching to help iron out weaknesses,” he said. “We do things in the first year that we wouldn’t have done 30, or even five years ago.

“We try to give students lists of words to learn, but the age of 18 is a bit late to be putting this right.”

The number of A grades awarded in Spanish this year went up by 9 per cent on 2007 in Wales. At 39.9 per cent, it was the highest number of entries in any language.

There was also a notable rise in German A grades - up from 26.2 to 32.9 per cent. French recorded the lowest gains, but was still up by almost one percentage point to 30.7 per cent. But entries for all three A-levels were down on 2007. In German, there were 937, compared with 987 the previous year.

Professor Williams, who is also dean of admissions, said the narrow gap between grades such as B and D made A-levels “a very poor guide to the quality of students”.

“In the end, you need to know what their percentage is, but we don’t know the marks, and that’s what bedevils university admission,” he said.

Professor Williams also emphasised the need to master the basics in languages, adding that “look and say methods” were inadequate at higher levels.