Hellllll no. will never happen. Not with millions of africans (yes millions.. tens of millions, actually. Dont forget there are 1 billion people in africa,
many of whom say they want to leave the continent. So even if only 1% try to, thats still 10M people on the move) walking on foot thousands of miles to get to the mediterranean and then somewhere around a thousand of them (many dont make it all the way to morocco) breaching the Spanish borders into Ceuta and Melilla every month or so. Not to mention those who attempt to get across by boat. The UK's decision to leave the EU was driven largely by europe's lethargic response to the migrant crisis, and they already spend huge amounts of money on security in gibraltar, so this proposal makes no sense at all unless morocco (which hasnt exactly had it easy either) solves it dispute with Western Sahara so that they can defend their border.
Its absolutely ridiculous that the article doesnt mention migrants even once, and im stunned that Boris Johnson, of all people, is even considering this project