The exact varieties might differ by trust/availability due to shortages.
But in general there will be the option of: paracetamol/codeine for early labour, gas+air, short acting opioids (e.g. pethidine, Meptid, diamorphine), and epidural. Some places might also offer things like sterile water injections into your back or remifentanil PCA.
There's also the option of you bringing your own TENS machine. Also, do not underestimate the relief a simple cold/heat pack can bring. Finally things your partner can do like massage or counter pressure.
I went into both inductions planning to start off on minimal pain relief, increasing as I felt necessary. Started out with paracetamol and codeine. Not sure they did anything, but couldn't hurt to try. Rapidly moved on to gas+air once contractions got going. Great stuff. Made me a bit dizzy initially, but once I was used to it, it was amazing for getting through contractions.
At 5cm I needed something a bit stronger. With my first, I had diamorphine injection. I was well and truly put of it with this. Asleep between the peaks of contractions out of it. It was good, but I have very few memories of that time, plus the immediate time post birth. With my second, I had an epidural. Didn't really want one, but labour had been protracted, and I knew all the other options might not last long enough to see baby delivered. It worked well, and I could still move my legs which I didn't expect. A few hours later the call was made for C-section (nothing to do with the epidural), so it was good to simply top up for the operation.
Wouldn't change anything if I had to go through the either delivery again. If I had a third, I might have a lower threshold for an epidural, but that would be it.