First ask for an exemption.
If they refuse that then send three people, very nicely dressed to one of their meetings and ask nicely again.
If they still refuse the exemption. Then turn up at their council meeting with the fully regaled Morris Team.
If that doesn't get you the exemption then send all your documentation to the local rag and TV and Radio stations. Get the support of as many other Morris and folk dance teams and local folk musicians as you can and stage a dance/song/demonstration outside the council offices.