LONDON - British Prime Minister Boris Johnson will tell social media companies on Tuesday to do more to tackle online abuse, condemning racist comments made against England's soccer players as coming from "the dark spaces of the internet".

Johnson's government has come under fire by some players and commentators, who say the Conservative prime minister and some of his top team have fanned the flames of prejudice and fuelled the abuse of three Black players in the soccer team.

But Johnson's spokesman said the prime minister had urged people to support the team and not boo them for taking the knee - a protest first made by American football quarterback Colin Kaepernick and followed by the Black Lives Matter movement.

"He said the abuse was utterly disgraceful and had emerged from the dark spaces of the internet," the spokesman said, describing an earlier meeting between Johnson and his cabinet team of top ministers.

"He said he would use today's meeting with social media firms to reiterate the urgent need for action ahead of tougher laws coming into force through the online harms bill," he told journalists.

After England's loss to Italy in the Euros final match on Sunday, Marcus Rashford, 23, Jadon Sancho, 21, and Bukayo Saka, 19, were the targets of abuse after they missed spot-kicks in a penalty shootout.

The government condemned the abuse but looks set to try to turn attention to social media companies, which have long been pressed by campaigners to better regulate what is published on their sites.

"We expect social media companies to do everything they can to identify these people," Johnson's spokesman said.

The issue of online abuse of players led to British soccer authorities briefly boycotting social media platforms before the European tournament, while Britain is planning legislation to force tech firms to do more.

But among the abuse, there has been an outpouring of support for the three players.

England soccer fans stepped up to defend Rashford by covering the racist abuse scrawled on a mural to the Black player in his hometown with messages of love and support for a "hero" who they said was a national role model. 

(Reporting by Elizabeth Piper Editing by Paul Sandle and Mark Heinrich) ((elizabeth.piper@thomsonreuters.com; 07979746994; Reuters Messaging: elizabeth.piper.thomsonreuters.com@reuters.net))