"What has gone wrong in the immigration debate is that we have now had decades of tough talk and administrative incompetence from both Conservative and Labour governments."

He also warned that because more British people worked overseas than there were foreign workers in the UK "if we simply pull up the drawbridge from one day to the next, we might actually find that we get a less welcome reception in other countries too".

Mr Clegg said other countries had developed ways of limiting immigration to certain areas and preventing them from moving on to more "crowded" areas.

"It is relatively easy, when people register to work, that they do so with local authorities so you know who is working where," he said.

"It is plausible. It works in other countries."