National curriculum tests finish in mid-May, effectively marking the end of key stage 2. Monica Gault, headteacher at Kings Road primary, Manchester, said: "It is a real job motivating children after the intense concentration has finished."
The Qualifications and Curriculum Authority said the tests have to take place when they do as there is a statutory requirement to report the reslts to parents by the end of the summer term
John Dunford, general secretary of the Secondary Heads Association, said: "We have long argued that the tests should be held at the end of June."
The Government has identified the transition to secondary as a weak link and has commissioned research, led by Professor Maurice Galton of Homerton College, Cambridge, which is due to be published in 2002.
He said: "The timing of the exams could be a contributory factor although this slump has been identified for many years."