It's impossible to talk about challenging the refusal to (re)implement single sex services without referencing the SC judgment and relevant legal challenges.
Exactly.
FWS can't force service providers to provide single-sex services. All it did was confirm that a service for, say, (women plus transwomen) must be non-discriminatory on its own merits (because, not being single-sex, it doesn't enjoy the blanket exemption from liability conferred by Schedule 3 Part 7).
Swift J in GLP v EHRC suggested that the following need taking into account but that the outcome will be fact dependent:
One. Are men suffering an unjustifiably less favourable outcome than women overall, because of the different criteria applied to the sexes for access to the service?
(Akua Reindorf thinks the answer to this is always yes, but I doubt we'll get a judge to say this - they'll only rule on the situation in front of them at the time.)
Two. Are women suffering an unjustifiably less favourable outcome than men overall, because (the) mixed-sex service affects women more adversely than men, for which the only remedy is to provide a women-only service?
(The answer in the Darlington case was yes based on fact evidence.)
All of this applies just as much to the Ponds as to the OP. And it means facing more litigation.
This is really unsatisfactory, because the Act has its exemptions (not all of which relate to sex, even) in order to serve specific societal goods, and it's being undermined.
What's the solution?
More regulations like the WR1992?
An amendment or reinterpretation of the Act to make services for (women plus transwomen) 'always illegal'?
A regulation saying that, if a service is provided for (women plus transwomen), then the provider must also provide a women-only alternative that is sufficient for demand?
Discussing it seriously is made almost impossible by the spectre of transphobia, the invisibility of women's needs, and, well, just the sheer stupidity. I am not very optimistic right now.