Professor Andrew Hamnett, the vice-chancellor of Strathclyde University, says coursework outwith the classroom is becoming "seriously debased" because examiners cannot be sure that pupils are doing it for themselves.

He says the problem is also leading to increasing numbers of university students plagiarising their coursework from the internet because they do not have the ability to seek out their own information.

Prof Hamnett made his comments as he prepared to chair a conference on the problem of plagiarism in the UK’s universities.

He said: "Examination boards are perceiving that the coursework in schools that goes towards exam marks is becoming seriously debased.

"There is a very significant minority of parents who are, in essence, helping their children beyond any normal definition of the word help.

"I’ve very little doubt that examination boards on both sides of the Border are looking at this because right through the system there is real concern about coursework – both at degree level and sub-degree level."

Prof Hamnett’s comments were last night backed by Judith Gillespie, the development manager of the Scottish Parent Teacher Council, who said many parents go too far when helping their children with their homework.

"I think that what Professor Hamnett is saying is remarkably astute because this has been around for quite a while," she said.

"The real impact of parents doing homework is that their kids become de-skilled and don’t learn how to do it for themselves. When I was a child I got no help at all from my family and periodically fell flat on my face with a piece of coursework. It was painful at the time, but it made me learn how to do things for myself."

The problem is so bad in England that one examination board has scrapped the coursework element of maths exams to prevent parents being able to influence their children’s marks.

But Mike Haggerty, the spokesman for the Scottish Qualifications Authority, said there were no plans to follow suit north of the Border.

He said: "You can measure the number of cases that come to our attention here in the scores rather than the hundreds."

Prof Hamnett also said the internet had made it easier for university students to access other people’s work which can then be cut and pasted into their own essays. He said he hoped that the plagiarism conference, which is taking place in London tomorrow, will result in universities being issued with guidelines which set out precisely what plagiarism is and let students know how to avoid it.

He said: "One of the things we want to do is clarify the rules of engagement so that staff know what they are supposed to tell students and so the students understand it better.

"There’s a large grey area. You can have a student who is essentially stealing someone else’s work and passing it off as their own in order to avoid doing work, while you might have a student who is quoting a passage but has forgotten to reference it.

"At Strathclyde, we’ve had a handful of very serious cases, but others where the students genuinely didn’t realise the seriousness of what they were doing.

"What I hope is that we can come up with a set of clear guidelines that universities can then adapt to their own statutes.

"We don’t want to criminalise a group of students, but at the same time we don’t want to treat the problem as some kind of jape, either."

A Napier University study published earlier this year revealed that lecturers were ignoring plagiarism by their students because dealing with it would give them too much work to do. The research found that as few as 27 per cent of staff in one department were "engaged in efforts to report plagiarism".

Professor Eric Wilkinson, from Glasgow University’s education department, said his own research suggested that about 20 per cent of parents were intensively helping their child on a regular basis.

"I do not think it is a massive problem, but it is happening. What parents need to do is to give their children direction to help them solve the question themselves, because if they just give them the answer the child is not learning anything," he said.

"Children also need to be encouraged to use their own abilities to argue a case rather than repeat what they read in a text book."

Prof Wilkinson said the extent of internet use among pupils was worrying. He added that the Highers system could also be encouraging pupils to learn verbatim from textbooks rather than to think independently.