First: I gave you numbers for the US, so you're pivoting to the UK in order to avoid addressing the salient point. But okay, here are some UK numbers. The numbers weren't great to start, and they've been getting worse; people in the UK may be okay with allowing adults to get gender-affirming care, but they're not okay with the NHS paying for it, and they broadly opposed gender-affirming care for minors. And paying for your own health care in the UK ain't exactly cheap.
If the plurality of people are broadly unsupportive of transgender equality (it's not a strict majority because there is a percentage of people that don't have an opinion), then the MPs that voted against transgender equality were doing what their constituents wanted.
If you have hard data showing that this the polling on this is incorrect, now is a great time to present it.
And yes, all of the scientific data that's credible demonstrates that trans people fare better with social acceptance, with access to gender-affirming care, when they aren't discriminated against. But that doesn't significantly sway public opinion on the matter. The majority of people that have an opinion on the matter as simply wrong.