The England team plans to take the knee before kick-off at their Euro 2020 games, despite players being booed by some fans at recent matches.
Where does the anti-racist gesture come from and why is its use at sporting events opposed by some people, including organisers of the Tokyo Olympics?
Where does taking the knee come from?
American footballer Colin Kaepernick took the knee during the national anthem before a match in 2016. He said he could not stand to show pride in the flag of a country that oppressed black people.
The anti-racist statement has since become a prominent symbol in sport and during protests.
It has been a feature of Black Lives Matter protests, including those following the murder of George Floyd.
Why are England players taking the knee?
Players and officials in the Premier League started taking the knee to highlight racial inequality and discrimination.
England manager Gareth Southgate said his players decided to continue during Euro 2020 and said "we feel more determined than ever".
Some fans have booed players kneeling before recent matches, but players said that was cancelled out by fans cheering.
Why do some people oppose taking the knee?
Some people say they oppose kneeling because they see it as a political statement and one which has no place in sport.
For example, education minister Gillian Keegan said taking the knee was "creating division".
Rather than demonstrating opposition to racism and support for the Black Lives Matter movement, it has been argued kneeling actually shows support for a campaigning organisation also called Black Lives Matter.
Conservative MP Brendan Clarke-Smith, a critic of the Black Lives Matter organisation, said that by kneeling England players are showing their support for its political goals. He said these included "crushing capitalism, defunding the police, destroying the nuclear family and attacking Israel".
Opal Tometi, one of the founders, said people were trying to discredit BLM "to distract, confuse and give people any excuse to not support this movement".
Gareth Southgate said the England team's actions were not in support of the Black Lives Matter organisation. He said: "We have got a situation where some people seem to think it is a political stand that they don't agree with. That is not the reason the players are doing it. We are supporting each other."
England defender Tyrone Mings said: "It's never been about supporting Black Lives Matter as an organisation. That was a cheap argument that people threw at the movement."
Will other teams take the knee?
Euro 2020 organisers Uefa said: "We urge spectators to show respect for teams and players taking the knee."
It said "any player who wants to demand equality amongst human beings by taking the knee will be allowed to do so".
The Welsh FA has confirmed its national team will take the knee during Euro 2020.
Scotland will stand before home games, but they will kneel with the England players when the two meet at Wembley.
The Croatia team does not plan to take the knee when they play England in the teams' opening game.
What about the Olympics?
The International Olympic Committee (IOC) - which organises the Games - has banned athletes from taking the knee.
IOC official Kirsty Coventry said it was "very concerned about the risk of politicisation of the athletes".
She referred to Rule 50 of the Olympic Charter, which bans any kind of "demonstration or political, religious or racial propaganda."
But UK heptathlete Katarina Johnson-Thompson is among those to say they might take the knee anyway. She said: "I'm not averse to taking a stand on the biggest platform."
What other protests have been made?
- At the Mexico Olympics in 1968, Tommie Smith and John Carlos gave the black power salute on the medal rostrum
- Basketball star Mahmoud Abdul Rauf refused to stand for the US national anthem in 1996 and described the US flag as a symbol of oppression
- LeBron James and other basketball players wore T-shirts with the words "I can't breathe" written on them in 2014, echoing the last words of Eric Garner, who died after being restrained by police officers in New York.