'Theresa May should reverse Ai Weiwei visa ruling'

As the Home Secretary stepped in to manage the growing furore, chair of the Home Affairs Committee Keith Vaz advised her to “stop digging”.

Labour branded the handling of the affair a “fiasco”, while the Lib-Dems said it looked like an attempt to avoid “diplomatic embarrassment”.

Ai was refused the visa and instead granted a shorter one to attend a Royal Academy show of his work in September, removing any chance of him still being here for an October state visit by China’s president.

Officials claimed the full business visa was refused because he failed to declare a criminal conviction, though he told them no conviction exists.

Mr Vaz said: “The Home Secretary should look at this and reverse it. He’s clearly been welcomed in other countries in Europe and putting a restriction on him is wholly wrong. There’s an old saying in politics that when you’re in a hole you should stop digging.”

Shadow home secretary Yvette Cooper wrote to Ms May demanding to know whether she had personally authorised the decision to deny Ai’s business visa. She said: “The diplomatic decisions of the British Government should prioritise those same rights that Ai Weiwei promotes and our democracy exists to defend.”

Lib-Dem leader Tim Farron said: “It is a clear demonstration of this Conservative Government’s lack of commitment to free speech and the arts.

“But, of course, it could be Number 10 is keen to avoid any diplomatic embarrassment with China’s president.”

In a letter to Ai, which he posted online, UK immigration officials wrote: “It is a matter of public record that you have received a criminal conviction in China, and you have not declared this. Exceptionally it has been decided to grant you entry clearance ... for your stated dates of travel to the UK.”

In a following post Ai said he had never “been charged or convicted of a crime”, adding: “[UK] representatives refused to admit any misjudgment.”

As the Government was accused of trying to ensure Ai is gone before Xi Jinping’s visit, Ms May called the decision in. The Home Office said: “This case did not come to the Home Secretary. She is now looking into it.”