my dog is 6 months old and every time we put the collar and lead on him he sratches and sits on the floor, he wont move untill he is litterally pulled. every time he then starts walk he trys scrapin his front to paws on the collar as he walks!
any one know why this is?
thanks

Probably because he isn't used to it. Put his collar on and leave it on, he'll get over it and eventually forget it's there. With the lead, let him play with it, you play with him too-drag it along and let him chase it. Then put it on him to take him to his dinner bowl, outside to toilet. Put his lead on several times a day for a few minutes always making sure that it's a positive experience for him and something good happens to him when he's wearing it eg give him treats, play games, go walkies.
When you are out on your walks, put his lead on every so often and take it back off again so he knows that the lead going on doesn't necessarily signal the end of the walk.

My dogs wear a collar from the 1st day I get them so by the time they go on a lead for the first time they are used to the collar

I also train them to do ALL heelwork off lead(in the garden obviously)Yes I do have to work a lot harder than people who use a lead as I have nothing other than my voice & treats/toys to keep the dog with me, but(& it is a really big but)when I put them on a lead I never(over the last 40 years)have any problems no pulling or refusing to walk etc because my dog wants to be with me & verbal commands keep them close. This makes "social"walking a pleasure

I  learnt this from a police dog handler many many years ago-he was ahead of his time in dog training & he never used the then popular chokers either

I too do exactly the same as Moonmaiden.  All of my dog's training is done off lead with games, toys and treats so they are learning to want to be with me and walk with me.  Then when the lead goes on they don't even notice it.  :)