British law (which isn't really a thing as whole anyway) isn't made and shouldn't be made just because "Barbara on MN doesn't like it"
How is public nudity as the law stands now damaging (carefully worded so people can't start using flashing or other illegal activity) or causing harm? Is it a quantifiable amount or is it just "Well, I don't like to see it?"
What quantifies an appropriate level of covering? Are bikini tops acceptable? What about vests? Is the law applied fairly across all - so men and women must cover up the same?
Where does breastfeeding come into it? Are women going to be expected to shut themselves away again because they might accidentally flash too much skin or show a nipple?
How does location work? Can you sunbathe topless at a beach? What about a local park? What about your own garden? What if someone happens to see you through your window?
Will nudist camps now be banned or will they have exemptions in place so as not to infringe on current freedom of expression? Will they have to increase security/membership systems/move into locations that can be fenced off?
This is just all off the top of my head quickly but the law would have to make sure it covered all of this, laid out very clearly
Now, I may be an outlier, but I'd rather we didn't have government departments tied up debating if shorts had to be longer than 2cm or 5cm and if parks and beaches were sufficiently different so as to incur different status with regards the law....