Two organizations representing university presidents and high school principals have submitted opinion papers to the Education Ministry expressing their opposition to a plan to hold college entrance examinations in December, in addition to the current tests held in January, group sources said Saturday.

The Japan Association of National Universities, led by Shigehiko Hasumi, president of the University of Tokyo, said in its opinion paper that the idea of holding entrance exams twice a year might "further deepen the confusion among applicants," the sources said.

The association said the proposal, advanced in April by the University Council, an advisory panel to the education minister, poses technical problems, such as maintaining the same level of difficulty for both tests to ensure applicants' trust in the examination system, the sources said.

Meanwhile, the National Association of Upper Secondary School Principals, headed by Hiroshi Mizutani, principal of Shinjuku High School in Tokyo, stated that holding exams in December would further shorten academic activities of third-year high school students, they said.

"Even now, third-year students have virtually no curriculum for their third semester because they need to prepare for college entrance exams. We cannot accept any proposal leading to a further shortening of the high school education period," one association member said.

However, the high school principals' association said in the paper that it supports increasing the number of exams because it would give students more chances to pass the tests.

The association had called on the ministry council to hold the second round of entrance exams in February or March, but the council rejected the proposal, saying it would make it difficult for colleges to start classes in April.