Ai Weiwei hasn't been able to leave China since the authorities confiscated his passport in 2011 and placed him under 24-hour surveillance. Despite his pleas for its return, the 56-year-old artist remains stuck in China and has been forced to miss several international shows, including Berlin gallery Martin-Gropius-Bau's retrospective Evidence, his largest exhibition to date.

Thankfully, some people still have his back. A new art project called Ai Can't Be Here is campaigning for the return of his passport under the slogan "if #AiCantBeHere 爱 (Chinese for 'love') can't be here". The Chinese character for love is also pronounced 'ai', hence the double meaning. 

Hundreds of Ai supporters have instagrammed images of themselves with the message, with the artist regramming select pictures on in acknowledgment. As an inventive, the project is also offering free printed t-shirts to people who uploads "Ai Can't Be Here" photos 20 times in 20 different places. 

"Every photo you upload is a piece of protest art," writes Zhao, the webmaster behind the project. "Like all protest art, your photo will have its own energy. And energy can change things."

Ai's passport was taken from him after he was imprisoned for 81 days in a Chinese jail under alleged tax evasion charges. According to him, the Chinese government still haven't explained why they've held onto his passport. 

This month sees the opening of @Large: Ai Weiwei on Alcatraz, his latest work. The site-specific installation will be constructed on Alcatraz Island by Ai's assistants and a team of volunteers, featuring 176 portraits of political prisoners and exiles made out of everything from Lego to teapots and bamboo. Edward Snowden, Nelson Mandela and Tibetan pop singer Lolo all form part of the exhibition.

While Ai could easily qualify as a subject, he's chosen to leave himself out of the show – and unless his passport is returned, he probably won't get to see it in the flesh too. To help with the Ai Can't Be Here campaign, head to aicantbehere.org.

Watch Ai Weiwei request the return of his passport below: