A British lawmaker was suspended Monday after a recording emerged of her using a racial slur during a Brexit discussion at a public event. In her remarks, which were first reported by the Huffington Post, Anne Marie Morris, the ruling Conservative Party’s chief whip, told attendees at an event focusing on the U.K.’s financial sector that the prospect of leaving the European Union without a deal would pose a problem.

That, of course, wasn’t the wording that got her into trouble.

“Now I’m sure there will be many people who’ll challenge that, but my response and my request is look at the detail, it isn’t all doom and gloom,” Morris said Monday in London. “Now we get to the real nigger in the woodpile, which is, in two years what happens if there is no deal?”

The remarks drew instant backlash from Morris’s fellow lawmakers. Tim Farron, the outgoing leader of the Liberal Democrats, said the comments “belong in the era of Jim Crow laws,” and several others—including members of Morris’s party—called for Prime Minister Theresa May to take disciplinary action. May ordered Morris suspended later that day, noting that “language like this has absolutely no place in politics or in today’s society.” Morris issued an apology the same day, calling her usage of the phrase “wholly unintentional.”

Morris isn’t the first British lawmaker to use the phrase—or face the backlash. In 2008, Tory leader Lord Dixon-Smith apologized for saying it during a session in the House of Lords, which he said “slipped out without my thinking.” The now-83-year-old lawmaker added: “It was a common parlance when I was younger, put it that way.”

The phrase, however, predates both Dixon-Smith and Morris, who is 60. According to the Oxford English Dictionary, its earliest usage can be traced to 1843 during the era of the Underground Railroad in the United States, when it was used in song lyrics to reference slaves who hid in piles of wood while fleeing north to freedom. The phrase later came to mean an “unknown factor affecting a situation in an adverse way,” or a hidden problem.

“It doesn’t really seem to take off as a figurative expression that lots of people used until the turn of the 20th century,” Dr. Lynne Murphy, a professor of linguistics at the University of Sussex, told me. “By the 1960s in America, it started to be a very unfavored phrase for obvious reasons. But Britain doesn't have the same history of racial politics that America does, and it perhaps didn't strike people as really offensive here as it did in America, so it continued to be used quite a bit.”

Indeed, the phrase’s usage appeared to peak in the U.S. in the 1930s before steadily declining between the 1940s and ’60s. It was during this time of decline that it began to gain popularity in the U.K.  The phrase was used at least 80 times in Parliament during the 1950s, according to the Hansard, which maintains transcripts of U.K. parliamentary speeches. Its usage dropped to 35 times in the 1970s, and by the 2000s was largely reduced to zero (with the exception of Dixon-Smith).

Tony Thorne, a linguist and lexicographer at King’s College London, told me the phrase’s popularity could be attributed to its usage in pop culture by novelists like Agatha Christie and W. Somerset Maugham, and even by Dr. Seuss. “The phrase was used by middle-class speakers in conversation in the U.K. the 1950s and ’60s,” Thorne said, adding: “Racial segregation wasn’t such a reality or such an emotive and crucial issue in the U.K. up to the ’70s, so ordinary people may not have been aware of the power of slurs. They should be today.”

Though suspended, Morris will still retain her spot as a member of parliament as an independent. While she is likely to continue voting with her party, the suspension reduces May’s fragile majority to 12, if you include the MPs from the Democratic Unionist party, the Tories’ partner in parliament.