"Home education", where children study at home rather than at school, is to face a review in England.
"There are concerns that some children are not receiving the education they need," said Children's Minister Baroness Delyth Morgan.
The government says there are no plans to remove the right to educate children at home.
But home educators' charity, Education Otherwise, said it was "infuriated" by the proposed investigation.
There is no legal obligation for children to be sent to school - but parents have to provide a suitable education.
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