Students sitting exams set by the Institute of Linguistics have been shocked by huge fee hikes.
Lynn Holman, a student at London's Morley College, said she had been told that fees for each of her four exams would rise from £65 to £250. The deadline for payment is the end of this month.
"The size and the suddenness of the announcement has appalled students," Ms Holman said. "I am no longer sure whether I can continue with this course."
Ms Holman, a mature student sitting the Diploma of International Communications, said many linguists were self-financing, unlike other students sitting professional examinations. She has written to higher education minister Margaret Hodge complaining about the rise.
Henry Pavlovich, chief executive of the institute, said a decision had been made to increase the price of all exams to cover costs previously subsidised from membership fees. "The institute receives no public funds and must cover its over-heads," he said. "These are not exams intended for personal interest and we must retrieve the costs."
Last year, he said, subsidies rose to £250,000 for the exams, which were extremely labour intensive as many oral tests required one-to-one supervision. In addition, Mr Pavlovich said more stringent regulations imposed by the Qualifications and Curriculum Authority had increased costs.