The Chinese government has placed the Beijing-born artist and activist Ai Weiwei under house arrest until midnight on Sunday 7 November. Ai, who designed the 2008 Beijing Olympic Stadium and whose work "Sunflower Seeds" is now on display at Tate Modern, was told earlier this week that his new £750,000 studio in Shanghai is to be demolished on Monday because it had been built without proper planning permission.

In a cheeky riposte that is likely to have angered the government, Ai sent an open invitation via his Twitter account (@aiww) for people to join him for a feast at his studio on the day before its planned demolition. Guests were promised hundreds of river crabs -- a popular Shanghai delicacy and whose Chinese name sounds like "harmony", a term used by the government to affirm its own success, but which has been adopted by critics to mock the regime.

Ai told the Daily Telegraph earlier this week that his new demolition order had come despite a personal invitation from the local mayor to build the studio two years ago:

It's all very strange. This guy [the mayor] flew to Beijing twice to personally invite me to build the studio and have one or two artists based there so they could build up the new art district. Now they say they want to knock it down. The local officials say the word has come from above and they're "sorry, but they can't do anything about it -- you have to destroy it", and no further explanation.

According to the Telegraph [2], Ai thinks his recent activism is the real reason behind the demolition:

Ai suspects that the order may be linked to two high-profile campaigns that have embarrassed and angered the Shanghai government in recent years. In 2008, Ai was instrumental in turning the case of Yang Jia, a man who stabbed six policeman to death after being arrested and beaten for riding an unlicensed bicycle, into an internet cause-célèbre. This year Ai made a documentary to highlight the plight of a Shanghai-based activist-lawyer called Feng Zhenghu, who spent more than 100 days marooned at Tokyo's Narita airport after being refused entry to China eight times by Shanghai officials.

Ai has continued to tweet since his house arrest, and has told people the event will still take place despite the fact that he isn't able to attend. Ahead of the sunflower seeds exhibition at the Tate -- well received by critics until visitors were barred from walking on them because of the ceramic dust thrown up -- Ai said to the New Statesman [3]: "Living in China can be very frustrating, but also very exciting. You see the possibilities and play the game." This week, unfortunately, it's a game he'll be playing from home.