I don't know if this has been covered before (sorry if it has).

While pulling away sometimes it seems quite lazy and going in 2nd and 3rd again sometimes it seem to hold back for a few seconds then it's off again.

It was like it when i first got it but seemed to of cleared it's self but now it's back really want to get to the bottom of it without going to main dealer if poss.

is this car a turbo diesel?? if it is, have a look at the intercooler pipes for any leaks or this could just be turbo lag, this is the second when the turbo is at idle you get low power and a second later you get full power.