As speaker of the British House of Commons, John Bercow oversees debates and maintains order. He is the ultimate authority, charged with deciding who can and can’t speak, inhabiting a role that dates back 800 years.

But his unconventional approach has attracted criticism that he has been undermining one of the most important positions in British democracy even before a row erupted last week on his long-standing opposition to allowing President Trump to address Parliament. Unless he changes his mind, Trump will not be speaking.