Slowthai said he does not condone violence after posing with an effigy of Prime Minister Boris Johnson's severed head.
The rapper held the head aloft during his performance at the Mercury Prize ceremony in London.
After an energetic act he proclaimed, to cheers from the audience: 'F*** Boris Johnson. F*** everything.'
British rapper slowthai sparked anger at the Mercury Prize ceremony by holding up an effigy of Boris Johnson 's severed head
The artist, whose record Nothing Great About Britain was nominated for the prestigious album award, has said his act was merely metaphorical, and said he does not advocate violence.
Explaining his actions, the 24-year-old said on Twitter: 'This 'act' was a metaphor for what this government is doing to our country, except what I did was present it in plain sight.
'No Boris Johnsons were hurt in the making of this slowthai performance.
'I don't condone violence in any form.'
In a statement posted online, he further said: 'Last night I held up a mirror to this country and some people didn't like the reflection.
'The people who isolate and divide us aren't the ones who will feel its effects the hardest.
'They're not the ones queuing at food banks, no the ones navigating Universal Credit and not the ones having to deal with systematic oppression and hate crime at the hands of privileged politicians who say what they want without fear and consequence
'We as a people are not being looked after and our best interests are not being served by those in government - this is their job and they're not doing it well enough.'
He was met with rapturous applause and cheers from the audience assembled at the Eventim Apollo in Hammersmith on Thursday.
There was anger online at the Boris Johnson stunt with one viewer saying 'someone's probably going to end up getting killed because of this move'
He lost out to London-born rapper Dave, who claimed the coveted Mercury Prize for his work Psychodrama.
Stormzy was among the judges who decided the winning album. He made headlines at the 2018 Brit Awards for his on-stage criticism of Theresa May.
The BBC live feed cut away from the rapper as he held up the effigy, but the audience responded with rapturous applause as slowthai (who spells his stage name with a lower-case S) left the stage.
But there was anger online with one viewer saying 'someone's probably going to end up getting killed because of this move'.
'This is really dumb, embarrassing and dangerous,' they said.
Another Twitter user said: 'I don't know which cause he thinks this is helping, but the answer is none. Horrible.'
'Imagine what the reaction would be if Johnson got on a podium for his next speech with a severed head with slowthai's face on it,' another asked.
Taking up a similar theme, another said: 'You can guess what the left would be saying if it was Jeremy Corbyn's head he was waving about.'
Raised by a single mother of four on a Northampton council estate, he has enjoyed a meteoric rise in the wake of his extended plays I WISH I KNEW in 2017, and RUNT, released the following year.
Some Twitter users reacted with fury to slowthai's stunt at the Mercury Prize last night
Awards host Lauren Laverne addressed the stunt without comment, saying: 'slowthai, with his own views there.'
Slowthai was one of 12 artists shortlisted for the Mercury Prize, which was won by London rapper Dave.
After the performance, slowthai, real name Tyron Frampton, took to Twitter to promote a £25 'F*** Boris' T-shirt along with another lewd