Mourinho said that there was a wider issue of racism in British society that had to be addressed.

"Society needs help. And then football is a micro-society. We need to eradicate any form of discrimination and in this case we are talking about racism. Football and society needs help," he said at a press conference on Monday afternoon.

It is understood the Premier League's anti-racism protocol was enacted for the first time during Sunday's match at the Tottenham Hotspur Stadium, after the matter was reported to referee Anthony Taylor by Blues captain Cesar Azpilicueta. Taylor informed the fourth official, who then liaised with Spurs' safety officer and the police.

One of the options open to the safety officer and police to tackle the issue would be an announcement over the public address system. Although this happened three times, it is believed there was only one isolated incident which was not repeated.

Nevertheless, the PFA's equalities officer Iffy Onuora insists it is now time for the "warm words" to stop and firm action to start.

He has called for a government inquiry into racism in the game and the need for tougher criminal penalties for hate crime, citing the tough sentences handed down after the London riots in 2011 as a precedent for how a message could be sent out.

Ministry of Justice figures published in 2012 showed that a total of 1,292 offenders were jailed for their part in the trouble with an average custodial sentence of 16.8 months – more than four times the average term handed down by magistrates' courts for similar offences.

"I've seen decisions made on public policy, when they had the London riots and people were getting sentenced to 10 years and things like that, it was a policy decision to send a clear message," Onuora told the PA news agency.

"Well is that only relevant in those particular circumstances? If you threw a five-year jail sentence at someone like this, that's a deterrent right there. That's a strong message that you're not tolerating it, rather than warm words after the event."

Home Secretary Priti Patel said: "Racism in all walks of life is completely unacceptable and football is no exception.

"Those found guilty of a racially aggravated offence under the Public Order Act can face a sentence of both six months in prison and a 10-year ban from attending all football matches.

"We fully expect the entire football community to work with the authorities to bring the perpetrators to justice so we can stamp this evil out of our national game."

Damian Collins, the MP for Folkestone and Hythe and who will stand for re-election as chair of the Digital Culture Media and Sport committee, wrote on Twitter: "Racist abuse must be driven out of football stadiums. A review on how we can do more to achieve this should also include stopping homophobic abuse and requiring social media companies to do more to prevent abusive attacks against players on their platforms."

Onuora believes the current political landscape has contributed to how certain individuals feel emboldened to act in this way.

"This isn't an accident, people (in politics) are very aware of what they're doing, they're appealing to a certain audience, they're making hay on it and the result is what we see – the spike in hate crime," he said.

The Football Association released a statement on Monday afternoon to say it was working with match officials, the clubs and the relevant authorities to establish the facts and take the appropriate steps.