(CNN) The British government is ready to intervene if soccer authorities fail to stamp out "vile" racist behavior at matches, a spokesman for the UK Prime Minister said Monday.
Sports authorities needed to crack down harder on the issue, Downing Street said, a day after Chelsea defender Antonio Rudiger indicated he heard monkey chants from the crowd in a game at Tottenham Hotspur.
The alleged incident occurred in the second half of Chelsea's 2-0 win against Tottenham. Rudiger, a German international, told his club captain Cesar Azpilicueta, who then alerted referee Anthony Taylor. Three announcements warning fans against racist behavior were made before the end of the match.
Tottenham said it had launched an investigation.
It was the latest unsavory act to mar European soccer and Prime Minister Boris Johnson's spokesman said the government wouldn't rule out taking "further steps" depending on how the sport's authorities deal with the issue as the season progresses.
"Racism of any kind has no place in football or anywhere else and we must confront this vile behavior," the Downing Street spokesman said at Monday's daily briefing with UK political journalists. "Clearly there remains more work to be done by the football authorities in tackling this issue and we are committed to working with them on this to stamp it out."
"The FA (Football Association), Premier League and English Football League have significantly stepped up their efforts, but we expect them to continue to prioritize this issue and to consult with both players and supporter groups, and we will be monitoring how the football authorities implement their plans through the season."
"We will continue working with the authorities on this, including the Professional Footballers' Association and we don't rule out taking further steps if required."
Sports minister Nigel Adams said Sunday it was "depressing to see today events." He was due to meet with Tottenham's directors later Monday.
The Professional Footballers' Association threw its support behind Rudiger and called for a government inquiry "into racism and the rise in hate crime within football and immediate and urgent action from an All-Party Group at the Department of Culture, Media and Sport to address this urgent issue."
Rudiger urged people to discuss the issue of racism in football. "If not, it will be forgotten again in a couple of days (as always)," he said on Twitter.
"I don't want to involve Tottenham as an entire club into this situation as I know that just a couple of idiots were the offenders," he added in a series of tweets. "I got a lot of supportive messages on social media from Spurs fans as well in the last hours -- thank you a lot for this."
"I really hope that the offenders will be found and punished soon, and in such a modern football ground like the Tottenham Hotspur Stadium with dozens of TV and security cameras, it must be possible to find and subsequently punish them."
"If not, then there must have been witnesses in the stadium who saw and heard the incident. It's just such a shame that racism still exists in 2019. When will this nonsense stop?"
The Premier League did not immediately respond to an email seeking comment.
Tottenham manager Jose Mourinho was asked about the issue in a press conference Monday -- a pre-scheduled briefing ahead of his team's game against Brighton at home on Thursday -- and said that racism in football was a reflection of a wider problem in society.
"I can repeat exactly that, I am totally, totally against racism in society and obviously against racism in my football world," Mourinho said. "I feel very sorry every time something happened and I will always support every decision the authorities can make. Society needs help.
"And then football is a micro-society. Do we need help? Yes. But society needs help. We need to eradicate any form of discrimination and this case we are talking about racism."
There have been a series of incidents in the Premier League recently. In early December, a 41-year-old man was arrested and bailed after allegedly racially abusing Manchester United's Brazilian midfielder Fred and English attacker Jesse Lingard. On the same weekend a 13-year-old Burnley supporter was thrown out of Tottenham's stadium for an alleged racist gesture aimed at South Korea international Son Heung-Min. Police launched an investigation.
Incidents have also been widespread across Europe in league games and European championship qualifying matches. Last week, an Italian football anti-racism initiative featuring paintings of monkeys received widespread criticism, prompting the Serie A league to apologize.
Former England defender Gary Neville, now a pundit on Sky Sports, accused Johnson of fueling racism in the aftermath of the incident in the Manchester derby and took aim at political parties again Sunday.
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It may be time for players to walk off the pitch when racist incidents occur, he said. "Maybe we have to empower the players to walk off the pitch and stop the entertainment while it is happening," Neville said on Sky.