The chief executive of Starbucks in South Korea has been dismissed after the company ran a promotional event using slogans that evoked a massacre of pro-democracy protesters during the country’s dictatorship era, sparking outrage and boycott calls.

The coffee chain launched a “Tank Day” campaign on 18 May for its “Tank” tumbler series. The date coincides with one of the most politically sensitive days in South Korea’s calendar, when citizens commemorate the 1980 democratisation movement in Gwangju, 167 miles (270km) south-west of Seoul.

The online campaign paired the date “5/18” with the slogan “Tank Day”, evoking the armoured vehicles used by the military regime to crush the uprising.

The Gwangju Uprising began on 18 May 1980 when paratroopers were deployed to crush student-led protests against martial law imposed by the military strongman Chun Doo-hwan.

Over the following 10 days, troops used bayonets, batons and live ammunition against civilians. Victims’ groups estimate that hundreds were killed.

The Shinsegae Group chair, Chung Yong-jin, whose hypermarket Emart subsidiary owns a majority of the company operating Starbucks Korea under licence, dismissed CEO Son Jung-hyun and ordered the dismissal of the executive who oversaw the campaign, according to the Yonhap news agency.

A Shinsegae Group official said in a statement that “as soon as Chairman Chung was reported on this matter, he ordered a strict and thorough internal investigation”, adding: “He considered this issue very serious and took the extreme measure of dismissing the CEO.”

The Starbucks promotion also featured the phrase “thwack on the desk”, which echoed the dictatorship’s infamous 1987 cover-up of the torture death of the student activist Park Jong-chul.

Authorities initially claimed that an officer “hit the desk with a thwack”, causing him to collapse and die, a lie that became shorthand for regime brutality when the torture was exposed, helping spark the nationwide protests that forced the regime to accept direct presidential elections.

The Gwangju-Jeonnam Memorial Coalition called the marketing “clearly malicious mockery”, adding: “We strongly suspect this is the result of management’s biased historical consciousness … being cunningly expressed through the mask of marketing.”

Within hours, Starbucks Korea pulled the promotion and apologised, saying it would implement stricter internal reviews. A company spokesperson said: “While unintentional, this should never have happened. We recognise the deep pain and offence this has caused, particularly to those who honour the victims, their families, and all who contributed to Korea’s democratisation.”

The spokesperson added that “Leadership accountability actions have been taken, and a thorough investigation is underway.”

President Lee Jae Myung, who had attended the Gwangju memorial that day, condemned the campaign on X. He said he was “outraged” by the behaviour of “low-class peddlers” – and said those responsible for the promotion must be held accountable.

The controversy has refocused attention on Chung. In 2022, he sparked controversy by posting “I hate communism” with “eradicate communism” hashtags online.

Such anti-communist rhetoric has long been associated with South Korea’s far right, which continues to circulate the dictatorial regime’s discredited narratives that falsely portrayed Gwangju protesters as North Korean sympathisers.

In 2023, Chung sent a congratulatory message to Build Up Korea, an organisation modelled on the US Maga movement’s Turning Point USA, and Starbucks Korea has since provided free coffee at its event. Chung is known for his close ties to the Trump family.

The Mart Industry Labour Union demanded Shinsegae Group halt its “anti-historical far-right behaviour”.