To ensure that no one was under any illusions about how he feels about the current UK Prime Minister, the 24-year-old rapper then started shouting: "F*** Boris Johnson! F*** everything! And there ain't nothing great about Britain" - a reference to his album.
Slowthai, whose real name is Tyrone Kaymore Frampton, was performing his hit 'Doorman' at the Eventim Apollo last night where he whipped off his top before pulling out the 'severed head' and holding it aloft.
As he held the fake head up the audience erupted into applause, before host Lauren Laverne rushed to say: "slowthai, with his own views there."
Doubling down, slowthai then posted a photo to his Instagram of himself posing with the dummy head and a beaming smile. He also shared photos of his range of T-shirts that feature the 'F*** Boris' theme and one which shows a cartoon Boris that appears to be... erm... getting acquainted with a map of the British Isles - if you want that image burnt forever into your mind, you can check it out here.
The bold stunt got mixed reviews with viewers, with some claiming he was inciting violence and that his actions were 'dangerous' and others heaping praise on the rapper calling him 'amazing' and 'brave'. Whatever you think, he's certainly managed to get himself a lot of headlines and social media attention...
Slowthai was nominated for his album Nothing Great About Britain, and was bookie's favourite before the ceremony, but on the night he lost out to rapper Dave, who scooped the prize with album Pyschodrama.
Dave brought his mum on stage with him to collect his prize (aw), where he namechecked a number of his fellow nominees, including slowthai and Little Simz.
Speaking after the ceremony Dave told the Guardian: "This is surreal. It is a massive honour and I am glad that I've been able to repay the faith that a lot of people have put in me... I have good days and bad days, but you see the team around me, my friends, my family, they kept me strong through this process."
As well as shiny new award for his mantelpiece, Dave also picked up £25,000 in prize money.Featured Image Credit: Instagram/slowthai