Jeremy Corbyn has called on the Russian Football Union and Fifa to take immediate action against anyone caught committing racist acts at this summer's World Cup.
The Labour leader, speaking at a Show Racism the Red Card event at Arsenal's Emirates Stadium, said he hopes the tournament is remembered for events on the pitch rather than in the stands.
In a speech to primary school children, Mr Corbyn, who is a keen Arsenal fan, said: "Anyone that commits acts of racist abuse in this club, or any other, are asked to leave the stadium straight away, and that's how it should be.
"I hope that in the World Cup this summer in Russia the authorities, Fifa, make sure that is the case in every stadium all through the World Cup.
"We want the World Cup to be brilliant as an exhibition of football, not of blind prejudice to each other."
Racist incidents in Russia have been one of the many talking points around the staging of the 2018 World Cup.
At the European Championships in 2016, scenes of violence saw some Russian fans accused of hooliganism, with police saying "the Russians came with serious intent to carry out barbaric violence".
Mr Corbyn added: "You know yourselves when you're playing on the pitch and you're doing well and everybody is cheering you, it's great, wonderful, everybody's behind me, I'm getting goals, I'm doing well.
"But when you're playing badly and you're not having a great game and people start getting on your back and shouting at you, that's not nice.
"But when they're shouting at you because you're black, because you're Asian, because you're Muslim, because you're Jewish, because you're Hindu, that is wrong and utterly disgusting."
Following the speech, Mr Corbyn was inundated with children asking for autographs before helping with activities and workshops.