Discussion of the 1989 protests and its brutal suppression at Tiananmen Square are taboo in China.

Chinese artist Badiucao, whose anonymous political satire infuriated Beijing and earned him comparisons to Banksy, on Thursday announced a protest campaign against Twitter over what he says is its pandering to China.

This is the second time the social media giant has come under fire in the last week over its handling of China-related content, after it apologised for mistakenly suspending accounts critical of Beijing -- just days ahead of the 30th anniversary of the brutal Tiananmen Square crackdown.

The 33-year-old Badiucao said he reached out to Twitter ahead of the anniversary and offered to create a special tank man emoji that would appear next to the hashtag #Tiananmen30.

Such emojis have been deployed on Twitter to mark a variety of special occasions and events, from the premieres of Hollywood blockbusters to national elections.

But the platform -- which is blocked in China -- told Badiucao it would not be able to collaborate with him on this anniversary because "emojis are limited resources at Twitter," according to an email exchange the artist shared with AFP.

"I was a bit confused," Badiucao told AFP. "How come they are a limited resource? I asked them if they had not enough graphic designers... or if it was a financial issue. I wasn't satisfied with their explanation that the decision was just routine."

The 33-year-old Badiucao reached out to Twitter ahead of the anniversary and offered to create a special tank man emoji that would appear next to the hashtag #Tiananmen30.

While Twitter said in that email that it was glad to be a platform for conversations about Tiananmen, Badiucao said the firm did not create a special emoji for the anniversary to avoid the wrath of Chinese authorities.

China's ruling Communist Party is highly sensitive to criticism, and discussion of the 1989 pro-democracy protests and their brutal suppression at Beijing's Tiananmen Square on June 4 are strictly taboo.

Ahead of the anniversary every year, authorities clamp down on activists and further tighten internet censorship to prevent any mention of the event.

"Very problematic"

Badiucao, who lives in exile in Australia, said that while Twitter does not work in China, companies from the country advertise on the platform.

"I think working with me is very problematic (for Twitter)," he said.

"They are thinking about the Chinese market, they want these advertisements from businesses for the company. So somehow they compromise their principles of free speech."

AFP asked Twitter about Chinese entities advertising on the platform, but the firm did not provide any details.

A source familiar with the matter at Twitter told AFP that the company did not have time to put out a special emoji for the Tiananmen anniversary, and that these are prepared months ahead of time.

The source also pointed to widespread discussions about Tiananmen on Twitter, and special collections of tweets curated by the firm on the occasion.

2020 anniversary

Badiucao said his protest campaign will begin Friday.

He hopes Twitter users will post selfies next to his -- or their own -- Tiananmen emoji designs with the hashtag #Tiananmen31 for next year's anniversary.

"Now I gave Twitter a whole year to do it," he said. "Let's see what excuse they come up with."

This is not the first time Twitter has faced criticism over special emojis.

In 2016, Donald Trump's campaign accused Twitter of unfairly restricting its content, in particular refusing a special emoji with a hashtag attacking Hillary Clinton, Trump's opponent in the race for the White House.

Weeks later, Twitter CEO Jack Dorsey was a glaring absence at a meeting between then president-elect Trump and a number of top tech executives.

Politico reported that Dorsey was "bounced" as retribution for the emoji refusal.