Reply #1: The standard in the US is "reasonable accommodation" [View All]

http://www.adl.org/religious_freedom/resource_kit/religion_workplace.asp

The school could reasonably accommodate her dress without interfering with the function of the school. It is not reasonable for her to demand gender segregation. If she wants to work in a public school, she should accept working alongside men. If segregation is more important to her than the functioning of the school, she should find employment elsewhere where they will allow segregation.

Jack Straw's office policy is wrongheaded. He is a public official and he does not have a good reason to demand that women remove a religious headscarf or veil when visiting his government office. Would he require Jewish men to remove their yarmulke or Christian women remove a cross pendant? It is an unreasonable policy for a government official.