Science lessons in primary schools have been given a lower status since national curriculum tests for 11-year-olds in the subject were scrapped, says a report by inspectors out today.
Many headteachers explicitly told education standards watchdog Ofsted they felt improving teaching in the subject was less important as a result of the abandoning of the tests and the view that inspectors regarded English and maths alone as the key subjects.
"Science is not taught every day in most primary schools," the report by Ofsted added. Nearly half failed to set any targets for pupils - seen as the best way of improving performance, particularly in maths and English. "This emphasises starkly the decline of science," it said.
"Most teachers in schools visited no longer provided pupils with time to revise or review their science knowledge and most prioritised English and mathematics above science, which is still a core subject in the national curriculum," added the report.
However, some schools - on hearing inspectors were planning to visit - organised "a special, and therefore atypical" day of science teaching.
The inspectors concluded: "It may be that these atypical lessons are not fully representative and that routine teaching of science is not always as good as the lessons seen during the inspectors' visits."
The downgrading of science in primary schools was one of a number of criticisms made in the study of science in 91 primary and 89 secondary schools visited by inspectors.
They also found that dull teaching - accompanied by a lack of practical work in the subject - was putting pupils off the subjects.
In some schools, not enough time had been set aside in the timetable for pupils to do practical work.
Exam entry figures also showed the subject was in danger of becoming elitist with "a stark difference" between fee-paying schools and non-selective state schools in the number of entries.
Almost one in four students in private schools sat A-level chemistry and 17 per cent physics compared with one in seven and 10 per cent respectively in non-selective state schools.
Girls, in particular, were likely to ditch physics - with only 11, 390 going on to do it in the sixth-form in 2011 despite 159, 745 getting two good GCSE passes in the sixth-form.
The report concludes: "Uninspiring teaching was one reason pupils gave to inspectors to explain why they did not wish to continue studying science."
In addition, a minority of secondary schools were "pre-occupied with tests and examination results as ends in themselves" rather than aiming to improve pupils' deeper knowledge of the subject. The report points out that getting good grades in science is not necessarily the same as "getting" science.
A spokesman for the Department for Education said that government reforms would mean more practical science work - both in exams and the curriculum.
He added: "Ofsted is right - pupils must learn through high-quality practical work if we are to produce the brilliant scientists vital for our economic prosperity.
"Our EBacc (the league table ranking measure for schools' GCSE results) is encouraging more pupils to take physics, chemistry and biology GCSEs and that is feeding through to A-level - where the number of girls taking three sciences is at its highest level for at least 14 years."