Corey Lewandowski, the controversial political operative who has steered Donald Trump’s presidential bid since its launch a year ago, has been fired as the billionaire’s campaign manager.

“The Donald J. Trump Campaign for President, which has set a historic record in the Republican Primary having received almost 14 million votes, has today announced that Corey Lewandowski will no longer be working with the campaign,” spokeswoman Hope Hicks said. “The campaign is grateful to Corey for his hard work and dedication and we wish him the best in the future.”

The New York Times, which first reported the news, cited a unnamed person briefed on the move who said that the campaign “had long planned adjustments to adjust to the needs of a general election campaign.”

Trump, who has been slipping in polls in recent weeks in his race against Democrat Hillary Clinton, was scheduled to meet with aides Monday about future campaign plans amid rising Republican anxiety. “Firing your campaign manager in June is never a good sign,” claimed Republican political consultant Kevin Madden after the announcement.

Lewandowski helped engineer the businessman’s unprecedented run toward the Republican presidential nomination. He was spotted at the presumptive nominee’s side during last week’s nationwide tour. While directing Trump’s presidential effort, Lewandowski clashed repeatedly with reporters and other campaign officials, including senior adviser Paul Manafort.