Again Vince Cable is incorrect about the benefits of immigration.
One of the reasons that there was a large vote for leave amongst British Asians is because there were lots of things said about being able to increase the number of immigrants from the Indian subcontinent, there has already been dissatisfaction with the fact that this won't be occuring.
Also, as is oft pointed out in these cases. Immigration has massive net benefits to the economy and therefore the populace. Already trained workers arriving, paying taxes, mostly leaving without having large impact on infrastructure.
Often what goes unnoted is the fact that it comes with the other four freedoms too. The UK has done massively well from freedom of movement of capital and goods etc.
Further overlooked is the fact that migration of UK citizens to other countries is also difficult, and that UK citizens have reciporocal rights in the EU.
Cable, as many do, is pandering here to the anti migration vote, whilst ignoring many of the other issues.