There is also ample evidence Brexit would adversely affect jobs, trade and investment. While there are lots of arguments for staying in, the three overwhelming ones for me focus on the three “C”s of competitiveness, certainty and co-operation. First, the UK economy benefits from being part of the single market of 500 million consumers. (Continental Europe was the first overseas market I took Travelex into, when we entered the Netherlands and Belgium in the mid-Eighties.)