The pomp of President Xi’s visit, which has been extended from the usual three-night stay to four in order to fit in a quick trip to Manchester, comes with particularly high expectations. Between the diplomatic dancing and proclamations of a “golden era” of international friendship are billions of pounds-worth of lucrative investments.Trade relationships between the UK and the world’s second-biggest economy have been growing steadily for the past decade. The Asian country now represents the UK’s sixth-biggest export market, taking 3.6pc of its goods and services. And China, for all the concern about its slowing economic growth and painful adoption of market principles, is coming here to shop. The red carpet will be rolled out next week for China’s first state visit in a decade. Everything from the type of fish served at the palace banquet to President Xi Jinping’s personal supply of bottled water has been planned in exhausting detail.The UK establishment extends an invitation to just one or two official state visits every year, and the Chinese stay has been proffered with all the available fanfare. Prince William travelled to Beijing in March to personally deliver the request, known as a manu Chinese President Xi Jinping, because it is written in the Queen’s hand.