Teachers have attacked the BBC and the Government's exams advisers for putting pressure on children by selling last year's primary test papers.
Advertisements for the test books from the BBC and the Qualifications and Curriculum Authority urge parents to ensure their children succeed in national tests at the ages of seven and 11.
One advertisement stated: "Want to help ensure your child succeeds in their National Tests? Then look no further. The ultimate revision aid from the BBC and QCA."
David Hart, general secretary of the National Association of Head Teachers, said: "It is quite inappropriate for even such august bodies as the BBC and the QCA to be flogging last year's exam papers.
"We are supposed to be playing down the tests, not adding more stress to seven and 11-year-olds. We need more pressure from parents like a hole in the head."
The packs, which are available as pound;9.99 books or pound;12.99 CD-Roms, have been advertised in the Radio Times and on the BBC's website.
The BBC's online shop explains that the packs contain an easy-to-use booklet for parents to help their children revise and "the actual 2003 National Tests".
Teachers who contacted The TES said the packs would also create problems because schools often used the previous year's paper as the children's mock test.
They will also upset a project being run this year by the Department for Education and Skills which will allow one in four primary schools to set seven-year-olds the tests from 2003.
Other teachers questioned whether it was appropriate for the QCA to be profiting from the papers.
Roger King, an interim headteacher of a Leicestershire school, said: "Can it be ethical that the authority is setting the exams, then making money from their 'official' status?"
The National Union of Teachers and the NAHT said they feared parents would use the packs to place greater pressure on teachers and children.
Mr Hart said that the packs would cause specific problems for schools taking part in the Department for Education and Skills key stage 1 pilot, which is running in 38 local authorities.
Schools in the project can this year use the 2004 or 2003 papers, or a mixture of both, to support their own assessments of students.
Although other publishers, including Letts, offer mock papers made up of a mix of past questions, only the BBC is licensed to sell the full tests.
Susan Ross, head of educational publishing at the BBC, said the packs had been produced for five years but that they had gained a higher profile this year because of the Radio Times advertisement.
She said the news of the key stage 1 pilot was "a complete shock".
"They hadn't told us about that," she said.
The QCA denied that the packs would undermine teachers' work. A spokeswoman said: "Pupils should be given some practice on past papers but not intensive coaching. When they sit the real thing they will be more familiar with the design and layout, giving them more confidence and making them more likely to achieve their full potential."