Japan ambassador’s Brexit warning: there won’t be a deal better than the single market

Koji Tsuruoka expected a quiet posting in a stable country. Then Brexit happened. He tells the Observer of his fears and hopes for manufacturing, trade and investment

Koji Tsuruoka is sipping green tea in Japan's splendid embassy in Mayfair, recalling how his first two years as Japan's ambassador to the UK have not gone quite according to plan. At least, they haven't turned out how his predecessors assured him they would. One after another, ex-ambassadors advised him, before he took up the position on 6 June 2016, that he would find the UK very "stable", and its politics "very predictable".

The attractions of London's ballet scene, opera and art galleries quickly lured him into thinking it would be "an excellent place to conclude my 40-plus years of diplomatic service in a very comfortable and quiet environment". British politicians and civil servants he met early on were almost all sure the EU referendum would pass peacefully by. "Almost 99% said that you don't have to worry because the British people don't make adventurous decisions. They said it was irrational to leave because of the economic conditions" And you know what happened."

Related: Brexit could cut manufacturing exports by a third, experts warn