rich47; Are you talking about the jobs which are at present 'over the channel' and going to disappear, or the jobs which are here, to disappear 'over the channel?
As you are not capable of formulating a question properly, I think you'd better stay where you are, whatever happens.
anyway, now we have worked out what the OP is. On what basis do you determine that British prosperity and jobs will "disappear"? Do you have any reasoning beyond your ire that the vote did not go your way?
Perhaps the usual numpties who voted to remain might actually have something constructive to say. As it is they don't so whatever the answer to the OP question is it isn't going to be good enough for them because they haven't thought about it either. Otherwise they would answer the question to show how wonderfully insiteful and knowledgeable they are.
But if you want an answer... and the question should have an IF not a WHEN at its core. However, work harder to make it happen is the obvious answer.
Here is a bet for you if you can find a bookie to take it;
Brexit won't happen and Trump will not last a full term.
So sorry to have ruffled so many sensitive feathers.