The situation has been with me that I left full time employment because the overtime at good hourly rates all disappeared.
I’d go back to cramming hours all the time again IF I were on the full timer’s rates!
The two big problems with this is that
(1) Not every full time rate is as cushy a number over agency flat rate as one depot to the next.
(2) Every time I try and get 13 weeks on the spin in, basic shift a week to qualify, I strangely get deleted from the database when I turn up for what would have been a week 13 shift otherwise. Hmm.
If there is no law that enforces terms and conditions without having to invoke a big tribunal process, then effectively it is just a form of bullying/abuse in the workplace.
“Look bud, if you don’t put up with this scam now that you’ve uncovered it, we just won’t use you any more. Your family will be evicted from no earnings long before any “tribunal” process goes through, and you might not even win that, let alone get any compensations!”
In the meantime, what proof do I have? - Convieniently being booted off the database works very nicely for resetting one’s parity pay clock to zero.
There’s no safety in numbers, because most other folk will be one hit wonders or full timer agency so they’ll have not noticed anything amiss.
Obviously, if they started booting the 40+hour agency bods off the books for week 12, then getting them to re-fill out the forms at the start of next week, it would then be totally obvious that it’s purpose is to abuse the law. I’m guessing that the folk putting in the macho hours are left alone, but part timers like me who, perhaps, look like they are taking the ■■■■ out of the system themselves in their eyes get the “treatment”.

After all, if it was all cut and dried, we’d all work a single day a week for the first 12 weeks, then cram it full time once we were on parity pay - right?

Meanwhile, I don’t even know if parity pay is worth chasing where I work, as I have no idea what rate full timers are actually on. I never seem to meet any to talk to any more, just other agency bods, and umbrella ones at that, suggesting in turn that they know even less about what fiddles are going on than I do.

As I’ve said before, the only firm I’ve come across so far that seems to “play it straight” regarding parity pay are Royal Mail.
On week 12 there, if they need you on week 13, you’ll get called in. They won’t pass over you, and give the job to the newbie with the plaster over his NHS glasses because they would like to sidestep their obligations.
Chalk up a mark to them.