Mumford & Sons banjoist Winston Marshall will take a leave of absence from the band in the wake of his tweet endorsing Andy Ngo’s book Unmasked: Inside Antifa’s Radical Plan To Destroy Democracy.

“Finally had the time to read your important book,” the banjo player wrote in a tweet this past Saturday, which has since been deleted. “You’re a brave man.” He quickly received backlash online, leading to his apology and announcement of his leave.

Ngo is a right-wing conspiracy theorist whose journalistic credibility has been repeatedly called into question; in a 2019 piece, the Columbia Journalism Review called him a “discredited provocateur”

“Over the past few days I have come to better understand the pain caused by the book I endorsed,” Marshall wrote in a tweet. “I have offended not only a lot of people I don’t know, but also those closest to me, including my bandmates and for that I am truly sorry. As a result of my actions I am taking time away from the band to examine my blindspots. For now, please know that I realise how my endorsements have the potential to be viewed as approvals of hateful, divisive behaviour. I apologise, as this was not at all my intention.”

View Marshall’s full tweet below: