The cabinet minister is expected to say that a Bedfordshire school was justified in its decision to stop a female Muslim pupil wearing a jilbab, a long gown, to lessons.
Last year the law lords overturned a court of appeal ruling that the
human rights of Shabina Begum had been violated by Denbigh High School, which had instructed her to go home and change into a school-approved uniform.
They ruled that the school had acted in accordance with both human rights and common sense in reaching the decision.
Lord Falconer is expected to tell headteachers that human rights are an engrained part of British culture and based on values such as freedom, equality, tolerance and respect and are not at odds with common sense.
It is thought that he will reassure NAHT members meeting in Bournemouth that they should not fear legal challenges under the Human Rights Act if they respond appropriately to issues, such as those raised within the Begum case, in their own schools.
However, the lord chancellor will also stress the importance for headteachers of considering the needs and sensitivities of the local community when drafting school policies such as those which cover the wearing of school uniform.
In March it was revealed that the government had issued new guidelines to schools giving headteachers the right to ban the wearing of the full Muslim face veil in schools.
Although some sections of the Islamic community welcomed the Department for Education and Skills (DfES) guidance, the Islamic Human Rights Commission (IHRC) described the new advice as "shocking" and accused ministers of failing to consult with Muslims in drafting them.
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