Twenty-five of the UK's top scientists and educators, including three Nobel laureates, have written to the Government urging it to make evolution a compulsory part of the primary science curriculum.
The joint letter to Education Secretary Michael Gove was organised after key reforms, included in the Rose review, were dropped just before the general election.
Under the proposals, which had been due to come into effect next year, evolution would have had a guaranteed place in primary science lessons. The Government confirmed earlier this month it would not implement any of the Rose recommendations.
The scientists behind the campaign to reinstate evolution, organised by the British Humanist Association (BHA), include Richard Dawkins, former professor of public understanding of science at Oxford University and author of best-selling The God Delusion, and Reverend Professor Michael Reiss, former director of education at the Royal Society.
The signatories say they are "deeply concerned that evolution and science form a core part of any revised primary curriculum".
"Evolution is the most important idea underlying biological science," they wrote. "It is a key concept that children should be introduced to at an early stage.
"Whatever curriculum reforms are made, we urge that there is teaching of evolution for all school-age children, and especially in the primary curriculum."
Explicit teaching of evolution had been included in the previous government's Children, Schools and Families Bill after campaigning from scientists, teachers and parents.
Andrew Copson, BHA chief executive, said it needed to be a mandatory part of the curriculum to overcome concerns about the teaching of creationism, especially as more schools gain freedoms over what they teach.
"It was a real victory for good education to have biology's 'big idea' included in the primary science curriculum for the first time last year, and it was with huge disappointment that we saw those reforms lost," said Mr Copson.
"As increasing numbers of schools, such as the new academies, will no longer have to follow the national curriculum, it is imperative that there is a firm basis for teaching evolution and natural selection, not least in light of the threat of creationism in science lessons in some schools."
A spokesman for the Department for Education said it would respond to the letter in due course and that the next steps on the curriculum would be outlined shortly.