A former adviser to Donald Trump who had come under fire from activist groups for supporting efforts to overturn the US election is stepping down from the board of directors at Duke Energy.

Dan DiMicco, the former chief executive of Nucor Steel who served as a trade adviser to Mr Trump’s 2016 presidential campaign and publicly supported attempts to challenge the 2020 election result, will retire from the North Carolina-based utility company’s board in May.

Shareholder activist group Majority Action, which has long been a critic of Mr DiMicco, was planning to campaign to expel him from the Duke board after the events of January 6, when a mob of Trump supporters stormed the US Capitol.

Mr DiMicco denied he was forced out, insisting that he was retiring in accordance with company policy that set an age limit for board members.

“My retirement has been in the works since I joined the board. To imply something else is not correct,” Mr DiMicco told the Financial Times. “Nobody’s running from anything.”

Mr DiMicco gave a total of more than $66,000 to 13 members of Congress who voted to overturn the election results, and posted multiple times on social media sites including Parler and Twitter questioning the legitimacy of Democrat Joe Biden’s victory.

Majority Action’s campaign against Mr DiMicco was part of a wave of action from shareholders seeking to hold companies and their directors accountable for backing those who sought, they claimed, to undermine US democracy.

“Duke is not the only company that will have somebody like this on their board,” said Eli Kasargod-Staub, co-founder of Majority Action.

“And I think [companies] are really going to have to face the choice of: is this the kind of person that they think should be in a role of governing their company . . . or is it finally time for such abhorrent views to no longer be centred in the boardroom?”

A Duke Energy spokesperson said it was “shocked and dismayed by the reprehensible attack on the Capitol last week”, adding that the company had halted all federal political donations for 30 days.

“The way members of Congress conducted themselves in this critical time will be an important consideration in future support,” Duke said.

Mr DiMicco said he supported Duke’s statement but that his position on the election had not changed.

“There are a lot of people in this country concerned about the election and things that took place,” he said. “My clear support is for having some process [to make sure] we had a fair and proper election. And that’s my right as a citizen.”

Groups such as Majority Action have tended in the past to focus more on environmental issues. The group in 2019 criticised Mr DiMicco’s stance on climate change in a statement supporting a shareholder resolution calling for Duke to disclose information on its political giving and lobbying. It led efforts to remove former ExxonMobil chief executive Lee Raymond from the board of JPMorgan Chase over his alleged denialism on the issue.

Now social issues are moving up the activist agenda, said Chris Krueger, managing director of the Washington research group at investment bank Cowen. “The efforts around January 6 are only going to increase in the coming days. I think we’re in the very early innings of this,” he said.

Like Duke, many companies have moved to suspend political donations since the riot at the Capitol.

On Friday New York City comptroller Scott Stringer, who oversees the city’s multibillion-dollar pension funds, called on companies to stop donating to members of Congress who objected to the certification of the Electoral College vote.

“Financial contributions by companies to these members of Congress who amplified unfounded conspiracy theories of election fraud is beyond the pale, and ultimately resulted in a violent insurrection orchestrated in part by white supremacists, domestic terrorists and neo-Nazis,” Mr Stringer said.

Companies that do not heed these warnings risk damage to their reputations, Mr Krueger said.

“If you’re not having those conversations as a board, or as a C-suite, I would argue, you are on the borderline of not exercising your fiduciary duty to shareholders.”