In comments made before the referendum but only now released to the Guardian, Mrs May conceded that “a lot of people will invest” in Britain “because it is the UK in Europe”.
Mrs May is reported to have said: “I think the economic arguments are clear. I think being part of a 500-million trading bloc is significant for us.
"I think, as I was saying to you a little earlier, that one of the issues is that a lot of people will invest here in the UK because it is the UK in Europe.
“If we were not in Europe, I think there would be firms and companies who would be looking to say, do they need to develop a mainland Europe presence rather than a UK presence? So I think there are definite benefits for us in economic terms.”