The prime minister and Priti Patel, the home secretary, have both condemned the criminal behaviour, but critics have accused them of fuelling the abuse, which Downing Street strongly denies.
Mr Johnson initially declined to call out England fans who booed players "taking the knee" in opposing racism, while Priti Patel described the act as "gesture politics".
The home secretary, who has posted several pictures of herself in an England shirt in recent days, said it was a choice for fans whether or not they booed and declined to say if she would do the same, adding: "I've never gone to a football match to even contemplate that."
After Ms Patel condemned the abuse of England players Marcus Rashford, Bukayo Saka and Jadon Sancho, their teammate Tyrone Mings said: “You don’t get to stoke the fire at the beginning of the tournament by labelling our anti-racism message as ‘Gesture Politics’ and then pretend to be disgusted when the very thing we’re campaigning against, happens.”
Taking the knee has become a prominent symbol in sport and during anti-racist protests in recent years, and England players chose to adopt the stance to show their support for the issue.
A number of Conservative MPs criticised the move because they view it as a political statement linked to the Black Lives Matter movement.
But England manager Gareth Southgate, his players and the Football Association have made clear that the team decided to take the knee "for each other" rather than expressing support for any political organisation or ideology.
A row broke out in June after England played a friendly match before the Euros started, when fans booed the players who took the knee.
Then on 3 July, when questioned on the issue, Mr Johnson told LBC radio: “I do not believe in gestures, I believe in substance.”
Four days later, Mr Johnson failed to call out those criticising the England players. A spokesperson for the PM said at the time that he respected “the right of those who choose to peacefully protest and make their feelings known”, adding: “On taking the knee, specifically, the prime minister is more focused on action rather than gestures. We have taken action with things like the Commission on Racial and Ethnic Disparities and that’s what he’s focused on delivering.”
Just a few days after those comments, the PM changed tack saying that he supported players taking the knee and told fans not to boo. A spokesperson said: "Yes. The prime minister respects the right of all people to peacefully protest and make their feelings known about injustices. The prime minister wants to see everybody getting behind the team to cheer them on, not boo."
As for the home secretary, in an interview with GB News in June, Ms Patel said football fans had a right to boo the England team for “taking the knee” in protest at racism.
She said the anti-racism protest associated with the Black Lives Matter movement amounted to “gesture politics” and dodged a question about whether she would boo herself.
“I just don't support people participating in that type of gesture politics,” she added.
Then on Monday, she tweeted: “I am disgusted that @England players who have given so much for our country this summer have been subject to vile racist abuse on social media.
“It has no place in our country and I back the police to hold those responsible accountable.”
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