Schools are axing practical training courses despite recognition by school leaders of their value to learners, according to newly-published research.
Three-fifths (60%) are either planning to cut the provision of vocational qualifications, or have already done so, the study found.
This is despite 85% of school leaders agreeing that vocational qualifications are valuable for their students.
In January last year, Education Secretary Michael Gove ordered 96% of GCSE-equivalent vocational qualifications to be stripped from school league tables, following recommendations made in the Wolf Report.
New research supported by the Edge Foundation, an independent education charity, and carried out by think-tank the Institute for Public Policy Research (IPPR), found that 66% of senior school leaders whose schools were cutting vocational provisions admitted the decision had been taken as a result of the changes to the performance tables.
Some 15% said the reason for reducing the number of vocational courses was that they did not believe the courses were valuable. By contrast, four in five (79%) of senior teachers interviewed agreed that vocational qualifications provided a firm foundation for school leavers to join the world of work.
More than two-thirds (69%) agreed that vocational qualifications were useful not only for those leaving school aged 16 but "offer a strong foundation for further study or training".
Jan Hodges, chief executive of the Edge Foundation, said: "We want high quality vocational qualifications to achieve parity alongside other educational routes for young people. Our concern is that in attempting to guarantee quality the Government has used a sledgehammer to crack the nut.
"Schools are now being forced to drop valuable technical, practical and work-related courses or risk getting no credit for the provision."
The Government announced a year ago that 70 vocational qualifications would count towards a school's GCSE performance in league tables in future - a cut from more than 3,000. The policy is part of a Government attempt to stop schools encouraging youngsters to take qualifications that boost their league table position but do not help a pupil's prospects.