Performance in England's secondary schools has improved but more progress must be made in the first three years, the government has said.

Publishing league tables which reveal an increase in performance against the government's yardstick, education minister David Miliband said that schools must push secondary pupils in their early years.

Forum Response: Association of Teachers and Lecturers

Gwen Evans, acting joint general secretary of the ATL, said: "We cannot afford another A Level type fiasco. The government's delay in responding to Qualification and Curriculum Authority's advice about the 2003 tests means that teachers have not been given adequate notice about the changes to the tests.

"It is therefore essential that the 2003 tests are used as a trial run. If the government doesn't take this problem seriously they risk drawing invalid conclusions about schools' performance in the future."

Forum Response: National Union of Teachers

Doug McAvoy, general secretary of the NUT, said: "League tables are a flawed system for assessing schools. Making them 'value added' tables merely adds a sophistication to that flawed system.

"Today's tables will be even more confusing for parents. They show that most 'value added' between 11 and 14 is in grammar schools. But the comprehensive schools do far better for 14 to 16 year olds. What are parents supposed to do with that information?

"The tables further compound the difficulties for parents in understanding that high league table position does not equate with high quality education. A school lower down the tables may well be providing very high quality education but not achieving the exam results demanded by the government."