Abstract For centuries, English law discriminated against Catholics and Jews. Those rules were mostly repealed in the 19th century, but surprisingly the law still says that a Catholic or Jewish person cannot advise the King on appointments within the Church of England or Church of Scotland. Ordinarily, new Church of England bishops are nominated by the King on the advice of the Prime Minister, but a Catholic or Jewish Prime Minister could not exercise that function; it would have to devolve on another Minister of the Crown. The article analyses the impact of this rule today, and, drawing on two interviews, considers how this rule was applied when Boris Johnson was Prime Minister. The article argues that the discriminatory rule should be repealed, allowing any Prime Minister, regardless of their faith or lack thereof, to carry out their duties in full.