JK Rowling has told her six million Twitter followers she thinks leading Republican candidate Donald Trump is worse than one of literature’s worst villains.

Following his call to ban all Muslims from entering the US, Trump received domestic and worldwide condemnation from both sides of politics.

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But a Tweet from Harry Potter author Rowling really cut to the core.

Along with a link to a USA Today article about Trump’s comments, Rowling Tweeted, “How horrible. Voldemort was nowhere near as bad.”

How horrible. Voldemort was nowhere near as bad. https://t.co/hFO0XmOpPH

— J.K. Rowling (@jk_rowling) December 8, 2015

Lord Voldemort, the xenophobic mass murderer intent on cleansing the world of non-magical people, was so feared that inhabitants of Rowling’s fantasy world dared not speak his name.

Unlike Voldemort, Trump has been considered somewhat of a harmless joke in the lead-up to the 2017 US election, but recently his ultra-conservative and racist comments have drawn growing ire.

Earlier this week, Trump called for a “total and complete shutdown of Muslims” entering the US until the country “can figure out what is going on”.

Also directing his comments towards Britain, Trump said “police are afraid for their own lives” in areas of London for fear of radical Muslims.

London mayor Boris Johnson responded to the comments on Tuesday, calling them “utter and complete nonsense”, and saying the reason he didn’t venture into certain corners of New York was for fear of “running into Donald Trump”.

“As a city where more than 300 languages are spoken, London has a proud history of tolerance and diversity and to suggest there are areas where police officers cannot go because of radicalisation is simply ridiculous,” he told reporters.

Fellow candidate Jeb Bush described Trump as “unhinged”.