Winston Marshall, a banjo player for English folk band Mumford & Sons, says he will take a break from the band after praising a book written by notorious anti-antifa troll Andy Ngo. “Over the past few days, I have come to better understand the pain caused by the book I endorsed,” Marshall tweeted. “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 blind spots.”

Marshall had tweeted support for the book Unmasked: Inside Antifa’s Radical Plan to Destroy Democracy written by Ngo, a self-described activist who documents his crusade against antifa in Portland, Oregon. The Los Angeles Times described the book as “supremely dishonest,” but Marshall tweeted that it was “an important book” and Ngo was “a brave man.” He has since deleted every tweet except for his apology.