Minister for Education, Mary Hanafin, has decided that all Irish-speaking schools - gaelscoileanna - will be obliged to teach at least half an hour of English a day from next year.
Until now, many gaelscoileanna have not taught English at all for the first two years of a child's schooling.
It is understood that schools with such a "total immersion" tradition of teaching Irish have until 2008 to implement the new policy which will apply to pupils in the second term of junior infants and upwards.
A spokeswoman for the Department of Education could not provide further details but said she believed Ms Hanafin had made such a decision.
Sinn Féin said the Minister was being "totally disingenuous" in relation to Irish language education.
Education spokesman Aengus Ó Snodaigh said all of the evidence suggests that the total immersion approach used for younger pupils has been "very successful".
"The Minister accuses gaelscoileanna of adopting an a la carte approach to the teaching of English. The opposite is actually the case," Mr Ó Snodaigh said.
"All those involved in gaelscoileanna - parents, pupils and teachers - have led the way in terms of education in this State. They have shown a commitment which is often lacking in government and have achieved very strong educational standards across all subjects including English."
He said the reality waws that it was the Government which had adopted an "a la carte" approach both in terms of support for the development of gaelscoileanna and the teaching of Irish in other schools.