Maybe over time we could get the number of economic migrants down to the high 10,000s, i don't know. It certainly wouldn't be at that level once we included asylum seekers however, who presently stand at a relatively low number in comparison. If combined with improvements in training programmes and apprenticeships, the UK can certainly aspire to a figure closer to 150,000. Further education aside, a sector like agriculture could enquire for workers in this country IMO. And provided that we allow refugees to work more readily, the government ought to feel a greater degree of flexibility in the numbers it accepts (an additional 20,000 p/a is possible in the short term i think).
We have also got to heed the concerns of individual communities, as it benefits neither the native nor incoming residents if the the public services are unable to cope. If a particular district stands to be adversely affected, and the chances of integration diminished, government should be acting to prevent such.
So...sure, i would like for accountability to reside at parliament here, but immigration isn't front and centre in my decision making.