Image via University of Denver/Flickr CC

Starbucks SBUX chairman Howard Schultz will step down later this month, the coffee chain he turned into a global giant announced on Monday.

Schultz, who has been outspoken on political and social issues, has long attracted speculation that he will run for office, potentially as a Democratic presidential candidate in 2020. In a memo to staff, he did little to squash those rumours.

“I’ll be thinking about a range of options for myself, from philanthropy to public service, but I’m a long way from knowing what the future holds,” Schultz said in the memo.

Schultz joined Starbucks in 1982 and has overseen the company’s global expansion. The company has more than 28,000 locations across the world.

Starbucks was rocked by scandal in April, following the arrest of two black customers at a store in Philadelphia. The two men were held after a store employee called police to say they were trespassing.

The company temporarily closed more than 8,000 US stores after the arrest for racial bias training. The incident was a blow for Starbucks which had previously tried – with mixed success – to enter the racial inequality debate by having baristas write “Race Together” on its coffee cups.

Schultz, 64, is estimated to be worth $3.1bn, according to Forbes. He has been an outspoken critic of Donald Trump, calling him “a president that is creating episodic chaos every day”. Schultz supported Hillary Clinton and Barack Obama.

He has championed a higher minimum wage, offered some Starbucks employees free college and been outspoken on some of the most divisive issues in US politics.

Last year he addressed employees following the fatal race riot in Charlottesville, Virginia.

“The moral fiber, the values, and what we as a country have stood for is literally hanging in the abyss,” Schultz said. “We are at a critical juncture in American history. That is not an exaggeration. We are at and facing a crucible in which our daily life is being challenged and being questioned about what is right and what is wrong.”

The company said Myron “Mike” Ullman would be the new chairman of the board, upon Schultz’s retirement. Schultz will keep the honorary title of chairman emeritus.

“I set out to build a company that my father, a blue-collar worker and world war II veteran, never had a chance to work for,” Schultz wrote in a letter addressed to past and present Starbucks employees. “Together we’ve done that, and so much more, by balancing profitability and social conscience, compassion and rigor, and love and responsibility.”