What do you feed him on?

How long is he left?

rune

This is typical terrier behaviour ime. They go from still to frantic in a millisecond and then don`t seem to be able to cope. I found standing still worked. My friend throws a ball or toy to her JRT and that seems to help. You could try teaching an alternative behaviour - ask for a sit and use a toy as a reward. Even if it`s a very rapid sit, at least the dog is responding, then you can throw the toy (I wouldn`t put my hands too close to an over-excited terrier!) and the dog will chomp on it like a dummy. Toys are good stress-relievers.
Overall I would look at calming the dog`s day. The change of routine will have upset him so establish another. Two or three short walks would be better than one long one. And two meals a day would be better than one. This will lessen the excitement of the food or walk.

He has two meals a day and two walks - about 40 mins in the morning and usually about an hour in the late afternoon. Weekends he goes into the garden sometimes as well during the day. He is left for about 6 hours during the day while I am at work so I do realise that he has a lot of energy to get rid of when I get home. I think a lot of it has to do with the change in routine - last year when I went back to work he had not been with us long and wasn't very attached to us. This year he is much more attached and, although I made sure that he was still left during the holidays, has obviously had a lot of people time over the six weeks. It is just a bit disheartening as I felt we had come such a long way and now it seems like we have gone back a long way.

I am going to buy a new tugger today and take that out with me - hopefully if he gets too hyper he will like to play with that.

I feed mine approx and hour and 1/2 after their walk but these do several miles of exercise so I want them really rested before they eat.
The jumping and nipping I feel isn't linked its more an attention thing IMO possibly due to change of routine.

Could you not play a ball game for 5 or 10 mins in the garden before his walk, this helping to lower his energy levels

Hope you find something that works for you and him