Martin Ruhs, director of the Oxford Migration Observatory, suggests it may be time for Britain to let its more labour-intensive farming slide.

ECONOMIST: Seasonal farm workers

"It is very difficult to assess how well the government is progressing toward its target of reducing net-migration to the 'tens of thousands', or to evaluate the effects of specific policy changes, " says Dr Martin Ruhs, Director of the Migration Observatory at the University of Oxford.

BBC: The truth behind UK migration figures