David Cameron's attempts to "turn a page" on Britain's relationship with China is overshadowed by an unwelcome diplomatic row with its Communist party leadership over censorship.
Downing Street was forced to make an official complaint to senior Chinese officials after a financial journalist on the Prime Minister's delegation was banned from attending the only official public event on the trip.
While no reason was given for ban the reporter worked for the financial wire service Bloomberg which has written critical stories about the party leadership.
A senior embassy official said that they had been warned two days before that Robert Hutton would not be welcome to attend the press conference in Beijing with David Cameron and his Chinese counterpart, Li Keqiang.
"We were told by the Chinese authorities that it would not be appropriate for you to attend," the embassy official told Mr Hutton.
When Downing Street were informed they tried with no avail to get the ban lifted. They then made an official complaint to the Chinese authorities.
A Number 10 spokesman said: "As soon as this issue became apparent on Sunday, we raised our concerns at senior levels and made clear it would be completely inappropriate to exclude journalists from the press statements.
"When we heard what had happened today we expressed our deep concern to senior Chinese officials about journalists being blocked."
The ban is embarrassing for Mr Cameron as he had hoped the focus of the trip to be about improving British Chinese trade and move on from a focus on human rights and freedom of speech.
But having said in the run up to the trip that "nothing was off limits" in discussions Downing Street had little choice but to make an official complaint - especially as Mr Hutton is a Westminster-based journalist travelling with Mr Cameron's delegation.
The Bloomberg website is blocked in China after it ran stories on the wealth of families of senior leaders including relatives of the president, Xi Jinping.
The US news organisation last month denied that it deliberately pulled a similar sensitive story following a New York Times report.
That said editors had been concerned its ability to report from China would be compromised if it ran the piece. Bloomberg said the piece was still in preparation.
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