Sikh, to find concealed weapons

Britain’s first Sikh judge has criticised schools for not allowing Sikh pupils to wear a ceremonial dagger called a Kirpan to school.
Typically made from iron, kirpans range in blade size from 3 inches (7.6 cm) to over 3 feet (90 cm), though Sikhs in the West wear kirpans with a blade of about 3.5 inches (9 cm). Most Sikhs wear the kirpan under their clothes and most people observing a random Sikh would not be aware that he was carrying a kirpan.
Well excuse me, but a three inch dagger is a three inch dagger, whether it’s a religious adornment or not and they have no place in schools.
Apparently Sikhs carrying the Kirpan are exempt from prosecution under the offensive weapons act, which to my mind is taking tolerance too far. No religion should be exempt from any law applicable to the general public, whether it is the established religion of the land or an ethnic one like Sikhism. Maybe I should make it an article of my (lack of) faith that I carry a loaded revolver about my person at all times. I wonder if I could claim discrimination over that?