Johnson was accused of Islamophobia in 2018 after he wrote that Muslim women wearing burkas "look like letter boxes."
Writing in the Telegraph newspaper, he said: "If you tell me that the burka is oppressive, then I am with you.
"If you say that it is weird and bullying to expect women to cover their faces, then I totally agree - and I would add that I can find no scriptural authority for the practice in the Koran.
"I would go further and say that it is absolutely ridiculous that people should choose to go around looking like letter boxes."
The Muslim Council of Britain accused him of "pandering to the far right" and he was placed under investigation by the Conservative party, before later being cleared.