So the big foreign companies that invest in Britain help to lift productivity.

ECONOMIST: Buttonwood

We should be supporting university students who come to Britain and invest in Britain, but we should also be having tougher action on illegal immigration.

BBC: 'Real problems' with migration target

Pro-European businessmen may be prompted to speak out by signs that international companies might be reluctant to invest in Britain if Europe goes ahead with a single currency but Britain remains aloof.

ECONOMIST: Europe