London’s Brick Lane, well known for its street art, has become a talking point after one of its walls was covered by slogans extolling Chinese Communist Party ideology.

Online videos showed a group of people had spray painted the big red Chinese characters on a white background overnight at the weekend.

The “core socialist values”, composed of 12 two-character words, are some of the most common political slogans under President Xi Jinping’s rule. Political propaganda in the form of red block characters on a white wall are a familiar sight in China.

The Brick Lane slogans have sparked debate online over whether they count as street art and how freedom of expression and political propaganda interact.

The wall has also become an arena for competing narratives – people swiftly added new graffiti criticising the Chinese government.

Some added “no” in front, or posted other messages or images taking issue with the spray-painted words. One picture shows an £800 fine issued on Saturday, citing “graffiti & flyposting” as offences.

Others were upset that the slogans covered up older works, including a tribute to a well-known street artist who died.

The socialist slogans, first revealed by President Xi’s predecessor Hu Jintao in 2012, include prosperity, democracy, civility, harmony, freedom, equality, justice, the rule of law, patriotism, dedication, integrity and friendship.

Although the slogans have attracted negative comment, it’s not clear if the people who painted them were being serious or ironic.

Wang Hanzheng, one of the creators who also goes by the name Yi Que for his art works, claimed the piece “didn’t have much political meaning”.

In an Instagram photo post, Mr Wang wrote in Chinese saying the group used the political elements as a coat “to discuss different environments”.

“In the name of freedom and democracy, it illustrates the cultural centre of the West, this is London’s freedom… Decolonize the false freedom of the West with the construction of socialism, let’s see what happens,” the post reads.

“Needless to say what’s the situation on the other side,” he added.

Mr Wang told the BBC “there is no question” that the 24 characters are “not only goals of China, but common goals for the world”.

Pictures of the wall immediately sparked strong reactions among Chinese speakers on social media.

Many inside China, mostly those who also defend the government, argued that what had been done in Brick Lane was freedom of expression and should be protected. Some said they were proud of this kind of “cultural export”.

But some nationalists also questioned whether it was a form of “high-level black”, a term often used by state media and social media users to describe people who use not-so-apparent language to criticise and satirise the Communist Party regime.

Outside China, the work has seen a flood of criticism.

“Obstructing freedom of speech is not a part of freedom of speech. The jargons you used cannot justify your brutal destruction of other people’s art,” a top-liked comment under Mr Wang’s Instagram post reads.

“Do you dare to go to Beijing and write democracy and freedom? If you dare, the home country you love will dare to arrest you,” another top comment wrote.

Mr Wang admitted the reaction had been more intense than he expected. He told the BBC he had been doxed and his parents harassed. “More and more people are using this subject for their own purposes and displaying maliciousness, this is not my intention,” he added.

Comments under his Instagram post of the work were no longer visible on Monday morning.

“This piece is not finished yet,” wrote another creator Gino Huang on Instagram.

“Like any other graffiti, being covered and discussed will be this wall’s final ending. We wish it… to turn into a part of this neighbourhood that can be seen every day when people pass it by, and to be included into a bigger narrative.”