Should there be skirting behind kitchen units

If it is a dry lined house, all the walls should be made of brick and block, and thus should have 50mm cavity insulation, so there shouldn't be any cold areas. If there are any gaps or holes in the brick work that should be covered by the insulation. Is the house covered by NHBC building standards insurance, and have you checked that the cavities are insulated properly? Is the draught coming from the area where the dry line finishes? If so, then you could cover this with expanding foam. It's normal for dry lining to finish short of the floor, because if you have a leak, it doesn't soak up the wall. It could simply be that colder air gets trapped in cupboards and in gaps where warmer air doesn't circulate. Hope this helps :-)

Its easy to expanding foam to fill the gaps in if the kitchen in its to hard to fit new skirting

nhbc regulations state that all walls dry lined or stud require skirtings, the only exception being tiled walls in a bathroom. The reason for this is that when the newly finished house has its inspection it must pass an air test. If as in your case it would appear that you have a draft, your property would not have passed or undergone an air test. I have vast experience of new build properties and have been made aware of this very issue in a kitchen in the past. There are several solutions to retrofit or "make do" but if your house is nhbc insured ask to see the air test results and take it from there.