Sounds as if he's just not quite ready for it all yet (the potty training)... BUT it will come, it's just about how you decide to get there.
I actually firmly believe that pull-ups do hinder potty-training. My DD regressed totally when I had her in them and when I asked her why she was doing wees in her special holiday knickers, she turned round and said "they're not knickers, Mummy, they're nappies!". Well, that told me!
Anyhow, if he's down to only one accident or two a day, then send him in pants with a change of clothes. You can also get training pants from Mothercare that are cloth, but with a Terry's towelling inner and a waterproof layer, so whilst they won't hold a full wee, they will save clothes from a "couldn't quite make it in time" accident.
However, if he's having an accident every hour, then I'm afraid to say, he's just not potty-trained and it'd be unfair on everyone (including him) to expect otherwise. In this case, you'd either have to keep him in pull-ups (which will be treated by everyone as nappies) or put him back in a nappy for a few months until he is ready.
Sorry to have to be so blunt about it, but if there's one thing I learned from the 16 months it took to potty-train DD, it's "don't even bother if they're not willing and able". DD would certainly get more upset, frustrated and would regress, the more pressure I put on her to perform.
DS is going into FS1 and no he's not fully potty trained. Its been an endless battle. Just when we think we have a few days of success we then have several days of none. Tomorrow he's back at nursery full time and I wonder what to do. I believe that the pull ups hindered him before but worried that its going to be nothing but piles of wet clothes each day. What would you do?
The last few days he seemed to not fully empty his bladder as he was going a tiny bit every twenty minutes and most times wouldn't make it to the potty.