Rights are about ensuring equal treatment, not coercing others into giving you or your children special treatment.
It can be done simply with a statutory instrument, using the power provided for by the safety clause in the Gender Recognition Act.
The promoters of the ban have used condemnation of abhorrent gay conversion therapy to promote a much wider ban.
It would make clear that the definition of the protected characteristic of sex (as in “sex discrimination” and “single-sex services”) relates to biology, and is not modified by a gender recognition certificate.