The reality of Britain's exit from the European Union — Brexit — grows nearer and clearer each week. Despite the promises of Brexit supporters that exit would benefit Britons, evidence is mounting that it will instead leave them much worse off. There are growing signs of concern from foreign investors, who put their money in Britain precisely because it offered access to the larger EU market. Brexit threatens that strategy and they have warned the government in London of the consequences.

The new mood was evident earlier this month when a delegation of Japan's top business leaders, along with the country's ambassador to the United Kingdom, warned that harmful effects on their operations resulting from the decision to leave the EU would force them to close shop in Britain. Their chief concern is the prospect of tariffs on goods moving between Britain and the mainland, but they also worry about new customs procedures and the end of the freedom enjoyed by London-based financial firms to conduct business throughout Europe. In each case, Brexit threatens to raise the cost of companies in Britain that service the European market. According to one estimate, Britain could lose 75,000 jobs in the finance industry over the long term without open access to the EU market.

Japanese companies made their concerns clear in a memo given to the London government immediately after the June 2016 Brexit referendum. Its logic was summed up by Ambassador Koji Tsuruoka after this month's meeting. "If there is no profitability of continuing operations in the U.K. — not Japanese only — then no private company can continue operations," he bluntly warned.