A balanced, five-A-level system is needed in order to safeguard Britain's scientific future according to the Astronomer Royal and outgoing president of the British Association for the Advancement of Science, Sir Martin Rees.
Speaking at a meeting to launch next week's annual BA Festival of Science, Sir Martin said that too many bright pupils are allowed to drop scientific subjects at the age of 16.
He backed the recommendation from the National Commission for Education that sixth-formers should study both arts and sciences in a broader A-level structure.
His comments come amid increasing concern about the low number of pupils taking maths and science A-level.
A consultation paper produced by the Government last year said that the proportion of undergraduates choosing science and engineering is continuing to fall.
Sir Martin said that, under the current system, a decision to choose arts or humanities at A-level "effectively forecloses" any possibility of a scientific future for sixth-formers.
"It's having very damaging effects," he said. "That's why we favour the recommendations of the national commission for a broad curriculum at 16-plus.
"We're doing everything possible to maintain the enthusiasm of young people at the stage when they're making what might be the irreversible choice to drop these subjects.
"The amount of movement has been disappointing since the National Commission first reported. We hope that Sir Ron Dearing will interpret his remit broadly when he reviews 16-19 education and will take note of the importance of a broader curriculum."
The BA has a particular interest in the commission as it was effectively born at the association's annual meeting in 1990 when the outgoing president, Sir Claus Moser, then warden of Wadham College Oxford, launched an attack on the British education system and called for a commission to investigate ways forward.
Sir Martin said that the difficulties facing science teachers were exacerbated by the apparently poor economic prospects for professional scientists. "When young people are deciding to embark on higher education, they do pay regard to their prospects," he said. "They are concerned if it seems scientists are valued less highly than accountants."
The annual Festival of Science, which starts this weekend at Newcastle University, is intended to generate public interest in a wide range of scientific studies, from allotropes (different physical forms) of carbon to pigeon-racing in the North-east.