A right-wing tabloid in the United Kingdom is facing criticism after publishing a headline describing writer Sarah Vine’s “niggling worry” about Prince Harry marrying biracial actress Meghan Markle.

“Yes, they joyfully in love,” reads the headline of Vine’s front-page story in the Daily Mail. “So why do I have a niggling worry about this engagement picture?”

The word “niggling” in and of itself is not racist, as it’s defined as a persistent discomfort or concern. However, it is also very close to the word “nigling,” a slur used by white supremacists to disparage black children.

Given that headline writers are often very careful and deliberate in the words they choose — especially if those words could provoke strong reactions, and thus help sell more papers — some critics believe that the Daily Mail intentionally used the word “niggling” as a racist dog whistle.

Check out some reactions from UK Twitter users below.

The word ‘niggling’ is not an accident. pic.twitter.com/rngWQvGMYE

— Danny (@shckldg) December 22, 2017

“niggling”
What she’s really thinking begins with “nigg–“
Could she make it any more obvious??
Wouldn’t wipe my arse with this…

— Nɪᴄᴋ Rʜᴏᴅᴇs (@__NickRhodes__) December 21, 2017

DM is pathetic. A “niggling” feeling. Next to Megan and Harry’s picture? Why that word? There is always an agenda

— ranting (@JustSmileRants) December 21, 2017

If your “niggling worry” takes 3 pages to explain then maybe you need to see a doctor. pic.twitter.com/LY5rUi01B0

— Tim Postins (@TimePositions) December 21, 2017

Why do I have a niggling worry?

For money, dear. For money. https://t.co/LBslDAkK1v

— Willshome (@willshome) December 22, 2017

‘Niggling’. Because that word wasn’t chosen on purpose or anything… pic.twitter.com/8nAFgrXOBy

— Ryan (@thisisryanon) December 22, 2017

TODAY: I don’t think dog-whistle journalism can sink lower than a columnist for the best selling newspaper in the country writing of her ‘niggling’ concerns over the first black member of the Royal Family. pic.twitter.com/HIwItlJJ6w

— The DM Reporter (@DMReporter) December 22, 2017