The competition authorities won't give a damn. They will of course instigate a review and then it will be pointed out to them that if they don't let the deal through then there will be thousands of job losses after Norwegian goes bust. IAG will then sit back and see who blinks first. If the deal is blocked they lose some cash as the shares plummet, investor confidence wanes and Norwegian go boom. Then they lose a competitor and get the cash back eventually. Or if they succeed then they get rid of a competitor and no doubt have plans for turning it around and fitting it within the IAG group and improving yields eg: Cargo, interlining etc.