Mother tongue learning materials for four communities have been approved under the new curriculum, locking out 38 tribes from the revised learning plan.
Kenya Institute of Curriculum Development (KICD) chief executive Julius Jwan said the available learning materials are in Gikuyu, Kikamba, Dholuo and Ekegusii. Dr Jwan told the National Assembly's Education committee chaired by Julius Melly that books are available for Gikuyu literacy Grade 1 and 2, Kikamba literacy Grade 1, 2 and 3, Dholuo literacy Grade 2 and Ekegusii literacy Grade 1.
The four tribes account for about 44 per cent of Kenya's population.
Matayos MP Geoffrey Odanga questioned why other communities that are estimated to be 42 tribes had not been included.
Dr Jwan said only materials from the four communities were submitted for evaluation.
"As KICD, we only evaluate what is submitted to us," said Dr Jwan, adding that the materials will be evaluated once they are submitted.
The new curriculum, set to be rolled out next year, has proposed teaching of mother tongue in nursery to Standard Three, but be made optional for upper school pupils.
According to the basic education curriculum framework, mother tongue will help develop oral, reading and writing readiness competencies to lay the foundation for language acquisition.
In the proposed structure, pupils will take two years in pre-primary and three years in lower primary.
"The aim of language activities at pre-primary school level is to enable learners to express themselves fluently," says the framework by KICD.
"The purpose of teaching language at this level is to also assist learners to improve listening ability, concentration, understanding and memory."