Dyslexia is a social fig leaf used by middle-class parents who fear their children will be labelled as low achievers, a professor has claimed.

Julian Elliott, a leading educational psychologist at Durham University, says he has found no evidence to identify dyslexia as a medical condition after more than 30 years of research.

"There is a huge stigma attached to low intelligence," he said.

"After years of working with parents, I have seen how they don't want their child to be considered lazy, thick or stupid.

"If they get called this medically diagnosed term, dyslexic, then it is a signal to all that it's not to do with intelligence."

He added: "There are all sorts of reasons why people don't read well but we can't determine why that is. Dyslexia, as a term, is becoming meaningless."

One in ten people in the UK - including 375,000 schoolchildren - has been diagnosed with dyslexia.

The condition is said to impair short-term memory and the ability to read, write, spell and do maths.

Supporters of the condition argue that dyslexics are intelligent people who have difficulties processing information and need extra help and time than others who are poor readers.

But Professor Elliott has claimed that the symptoms of dyslexia - such as clumsiness and letter reversal - are similar to those seen in those who simply cannot read.

He argues that the condition should be rediagnosed as a reading difficulty.

His comments provoked fury among dyslexia campaigners.

John Rack, head of research and development at the charity Dyslexia Action, denied that the disability was a middle-class phenomenon.

He told The Times: "There is ample evidence that dyslexia exists across the spectrum and the argument that there is no consistent means of identifying it is one cited by people who don't know enough about the subject."

However, other experts have suggested that parents are putting their children forward for reading ability assessments to "get them off the hook".

Dr Michael Rice, a dyslexia and literacy expert at Cambridge University, said: "There is a sense of justification when children are diagnosed.

"It gets them off the hook of great embarrassment and personal inadequacy."

According to Professor Elliott, dyslexic university students are gaining an unfair advantage by getting extra time for their studies and many are getting diagnosed simply to get up to ยฃ10,000 worth of equipment including laptops and extra books.

University lecturers have complained about students "milking the system" by pretending they have the condition.

One lecturer who teaches in the South-East said:

"On one degree course I teach, about one quarter of the students get help with their coursework and other assistance because they have this label. You become quite cynical."

The number of students who receive disability allowances at university has risen to a record 35,500 at a cost of ยฃ78.4million a year.