Children are growing up lacking confidence, struggling to communicate and unable to make friends because of the "schoolification" of the early years, it was claimed.
The Professional Association of Childcare and Early Years (PACEY) insisted that toddlers needed more time to play to give them the opportunities to develop social and emotional skills before the start of formal education.
It was claimed that Coalition's reforms of early education were too focused on getting children "school ready" rather than allowing them to develop naturally.
This includes the possible introduction of a new baseline test for five-year-olds in England and qualifications for child care staff that make little reference to learning through play.
The comments came as a survey by PACEY found that fewer than one-in-20 teachers and a third of nursery staff believed it was necessary for children to focus on basic reading, writing and arithmetic in the early years.
Most wanted a stronger focus on boosting social skills, developing their curiosity and independent personal care, including the ability to use the toilet without assistance.
It comes just weeks after a powerful lobby of teachers and academics wrote to the Telegraph calling for the school starting age to be delayed by up to two years because of the pressure being put on children at an early age.
Liz Bayram, chief executive of PACEY, said: "Our research shows there is growing concern about the ‘schoolification' of the early years.
"Whilst no one would deny that supporting all children to achieve their full potential is critical, PACEY is concerned that educational attainment is becoming the dominate force in early years.
"Teachers and childcare professionals are concerned that the importance of play and how it supports children to be confident, communicative, sociable and curious individuals is being lost."
Researchers interviewed 500 childcare workers, 160 teachers and almost 1,500 parents as part of today's study into the state of early education, which was carried out in conjunction with the Netmums website and the National Union of Teachers.
It found that only a third of nursery staff, 26 per cent of parents and four per cent of teachers believed that a grasp of the three-Rs was "essential to school readiness".
Three-quarters of all respondents cited independence with personal care, ability to spend time without their parents and strong social skills as the most important aspects of early education.
The study also quizzed people on the compulsory education starting age, which is currently set at the September after children turn five. Some two-thirds of parents believed the starting age was correct, but this dropped to 46 per cent among teachers.
Cathy Ranson, editor in chief of Netmums, the parenting website, said: "For parents, the term ‘school ready' is not about how proficient their child's handwriting is or what stage reading book they are on. It's more about the practical aspects such as whether they can do up their own coat, open their lunchbox easily, or simply have the maturity to be able to listen and understand instructions from teaching staff."
A Department for Education spokeswoman said: "The simple fact is that a third of children start school without basic language and communication skills. In poorer areas, this rises to more than a half.
"Good quality early years education, which is teacher-led, has been shown to be beneficial for children, especially those from low income backgrounds. It makes a difference to young children's lives and gives them the social skills and confidence to have the best start in life.
"It is important for parents to have a choice of different approaches - including free flow play and structured learning - so they can choose what works best for their child."
-reprinted from the Telegraph