Eton, St Paul’s and Winchester College are among dozens of independent schools boycotting league tables by refusing to release their exam results.

Their head teachers claim that the rankings penalise schools that take weaker pupils and encourage the teaching of softer subjects.

Martin Stephen, High Master of St Paul’s School, said: “The reason we are pulling out of league tables is we are coming dangerously close to factory-farming children.”

Others argued that the GCSE and A-level “monolith” no longer exists because some schools now offer alternative exams, which are hard to compare. Graham Lacey, deputy head of Sevenoaks School in Kent, said: “We offer the International Baccalaureate instead of A levels, so league tables don’t do us justice. It’s a far more complicated qualification than A level and harder to quantify. It’s like comparing chalk with cheese. Our results will be on our website next month.”

Sevenoaks also offers international GCSEs, which are widely regarded as tougher than GCSEs but are not recognised by the Government. Mr Lacey said: “Many schools have deep concerns about modular GCSEs.”

Almost 50 independent schools, including Radley and Marlborough colleges, have withheld their A-level results. A similar number are expected to do the same with the GCSE results being published today.

However, many leading independent schools will publish them. They include Brighton College, where Rich-ard Cairns, the Headmaster, said: “There is a sense among some heads that parents place too much emphasis on league tables. My own feeling is that . . . parents should be given as much information as possible so that they can make a truly informed choice.”

Explore Education

• Schools

• GCSE & A Level Results

• Good University Guide

• Sunday Times University Guide

• Student

• Young Times

Times recommends

• Google generation has no need for rote learning
• Left-handers do 'less well' in exams
• Nativity comic books for multicultural Britain