Nearly half of secondaries still do not give pupils a chance to take separate GCSEs in physics, chemistry and biology, despite a recent sharp rise in schools that do, the public spending watchdog reported today.
Secondaries in deprived areas are the least likely to offer the individual "triple science" GCSEs even though it is their pupils who would benefit most, according to the National Audit Office (NAO).
Its report on science education also warns that the Government is likely to miss targets on recruiting physics and maths teachers, and that school science labs are not up to scratch.
Take-up in A-level chemistry and maths have improved in the past five years, the NAO found. But take-up of A-level physics had "increased more slowly".
The report says evidence has shown that pupils who opt for separate physics, chemistry and biology GCSEs are more likely to choose science subjects at A-level and achieve higher grades.
Pupil take-up of the individual triple-science GCSEs rose by almost 150 per cent between 200405 and 200910, the report found, and the NAO says the Government is "making good progress" towards making them available to all pupils by 2014.
But the latest figures show almost half of state secondaries are not offering pupils the option. The statistics date from June 2009, a year after the previous government's "entitlement" that all pupils "above average" at key stage 3 could take the three separate GCSEs, came into effect.
Heads have said they expect a further rise in take-up this year. But the entitlement is non-statutory. It amounts to an encouragement from government and only applies to pupils who schools think will benefit.
The NAO cited research which found pupils from deprived backgrounds made comparatively larger improvements at A-level science and maths if they took triple science GCSEs than other pupils.
But its analysis showed that the more deprived an area, the lower the availability of triple-science GCSEs. "This more specialised curriculum is lacking in the areas where it could have the greatest impact on take-up and achievement," the report said.
Specialist science, technology, engineering and maths schools also demonstrated better GCSE and A-level results, but they were also less likely to be an option for pupils in deprived areas.
The previous government set a target to bring all school science labs up to a satisfactory standard by 200506 and to a good standard by 2010 but had not collected the data needed to measure its progress, the NAO said. The latest research from 2006 suggested this target would not be met until at least 2021.
The report also predicts that targets for increasing the number of specialist chemistry teachers will be met, but those for physics and maths teachers will not.
Amyas Morse, head of the NAO, said: "The Department for Education has focused its resources on improving pupil take-up and achievement in school science and maths, and has made good progress in areas such as A-level maths and GCSE triple science. To make further progress, what's needed is a more joined-up approach."
Schools minister Nick Gibb said he welcomed the NAO report and would take on board its findings.
"Educating the next generation of scientists is crucial if we are to compete with the best in the world," he said. "The best way to engage young people with science is for them to be taught a strong knowledge-based science curriculum by an enthusiastic science teacher. We want to attract the highest-quality entrants into teaching and that is why we are expanding Teach First, Teaching Leaders and Future Leaders and putting teachers at the heart of our upcoming white paper."