Children aged four are to be tested just days after they start school.
But early years campaigners insist the assessment will damage children's confidence and lead to many infants being branded a 'failure'.
However, the Government said it would be a 'simple check of a child's level of understanding, for instance, counting and picture or letter recognition', carried out in an informal setting.
Results from the 'baseline' reception class assessment will be used to chart pupils' progress over a seven-year period before they sit formal SATs exams at the age of 11.
The announcement was made as part of sweeping reforms to the exams system and league tables in England at all stages of the state education system.
Ministers said the assessments were informal and would mark out schools with difficult intakes that go the extra mile to improve children's performance.
It was also claimed the reforms would provide 'no hiding place' for schools that allow bright pupils to 'coast'.
This includes a new externally-set test in spelling, punctuation and grammar test for pupils aged seven – on top of existing exams in reading and maths taken at the same time.
Russell Hobby, general secretary of the National Association of Head Teachers, said: "We welcome the emphasis on progress as the defining measure of school performance and the recognition that there is more to primary education than preparing for secondary education."
But Liz Bayram, chief executive of the Professional Association for Childcare and Early Years, said: "PACEY remains firmly opposed to baseline testing for four-year-olds and is unconvinced that the Government's approach will best support a child's early development.
"This change has more to do with monitoring school performance than supporting children to have a strong foundation for future learning.
"As our school readiness research has shown, preparing children for school involves much more than just early reading, writing and maths skills.
"We believe there should be equal consideration for children's physical, social and emotional development as well as educational development, fostered through a play based approach to learning."
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