Yes, my understanding was that it was largely the equal pay claim. It was for an obscene amount.
Tbf, I'm a little on the fence about the whole equal pay decision. I wholeheartedly support equality, but the issue wasn't men getting paid more for the same work (e.g. male vs female cleaners). It was a ruling about 'work of equal value'.
It seems it essentially started with cleaners arguing that they should be paid the same as refuse workers. However, the jobs aren't really comparable IMO - I say that after having worked for three years at the UK's second largest waste contractor and having also spent 4.5 working for a 'top 3' cleaning/security provider.
Refuse collection is the second most dangerous job in the UK. They have a high incidence of being assaulted by angry members of the public, being hit by impatient cars that mount the kerb to drive past (often hitting the refuse collectors as they pull the bins out from behind the truck), and they regularly encounter used syringes/dogs and all manner of things that you're much less likely to find in a typical office/workplace environment.
And many get up at 03:30am to work in the pouring rain and freezing temps. It's really not a comparable job IMHO and it almost feels like the decision may have been pandering to public opinion or the simplified view that 'they're both concerned with removing waste'.
I'd like to think that they did a robust comparison but I don't have much faith in governmental bodies nowadays I'm afraid!
https://uk.indeed.com/career-advice/finding-a-job/most-dangerous-jobs