"Frankly the schools are scared of us," said the principal of a college in the south-west of England. "We offer a much bigger choice and our results are up and up."
The principal also accused heads of bullying pupils who had applied to colleges. He added: "When some schools with small sixth forms get a request for a reference then the head interviews the student," said the principal. "He will say, 'why have you applied to college?' He browbeats the student. So as a result we do not ask certain schools for a reference until the person has been accepted."
He also cited other instances of schools refusing to deliver college prospectuses and generally "bad-mouthing" them.
"The decision you make at 16 is as crucial as the one made when you move from primary to secondary, it's as important as that. And the information students need is simply not being provided."
The principal's remarks came as the Association of Colleges published research showing that schools withhold the names and addresses of Year 11 pupils, misinform students by saying college courses are full, and only encourage less able students to apply.
Three-quarters of colleges which responded to a survey had asked the local careers service to take action, but only two-fifths had done so.
David Gibson, chief executive of the association, said: "This survey confirms what many colleges are reluctant to admit for fear of making the local situation worse. Many pupils and parents are in effect having their choices removed from them without knowing it.
"Colleges add just as much attainment to each student's starting point as do schools, yet they do so at up to 20 per cent less cost for an average three A-level package, so the public is paying for this malpractice as well as the pupils."
Meanwhile, colleges reported improved A-level results. At Bedford College, in Bedfordshire, pass rates were up 4 per cent against a 0.7 per cent increase nationally.
West Thames college, in Middlesex, saw A-level passes rise by 8 per cent, and the successes of evening class students up by nearly 25 per cent. Yeovil College achieved a 100 per cent pass rate in 17 subjects.
Tower Hamlets college's science results were all above the national average.