Nick Clegg said the issue of immigration was "the biggest dividing line in politics today" and branded plans for a cap "arbitrary", "pointless" and "distracting".
In an article for The Sunday Times (£), Mr Clegg wrote:
Sticking a big no-entry sign on the cliffs of Dover may be politically popular, but at a huge economic cost. What would happen if tonight every European living in the UK boarded a ship or plane and went home?
Are we really that keen to see the back of German lawyers, Dutch accountants or Finnish engineers? Do we want the NHS to fall over and the City of London to grind to a halt?
Britain would be one step closer to the exit, even though walking away from Europe would cripple the economic recovery that's been so hard won.
More top news
The RSPCA are trying to find who is responsible for leaving the trap out as they are warning they could be breaking the law.
Fine start to the week for most but turning wet and windy from Wednesday.
Thousands of people have lined the banks of the Mersey to see Cunard's three flagship ocean liners sail down the river.