Bulgarian Football Union (BFU) president Borislav Mihaylov has resigned from his role after racist abuse was aimed at England's players in Monday's European Qualifier in Sofia.
England ran out 6-0 winners in their Euro 2020 qualifier in Sofia, but the game was marred by the torrent of racist abuse directed at their players, with the game twice halted during the first half.
The events inside the Vasil Levski National Stadium clearly resonated with the country's highest office, with Prime minister Boyko Borissov issuing orders for Mihaylov to resign immediately.
However, while Mihaylov's letter of resignation is to be presented to members of the country's FA Executive Committee on Friday, Sky Sports News has learned that he could yet remain in charge.
Bulgarian Football Union vice-president Yordan Letchkov has said he will not accept Mihaylov's resignation at the meeting on Friday.
The BFU Board will vote that day on whether to accept Mihaylov's resignation - and at present he remains the most powerful man in Bulgarian football.
Less than an hour after Mihaylov's resignation announcement, more than 20 police officers swept into the BFU headquarters in Sofia, believed to be searching for documents related to some Bulgarian referees.
Ahead of Mihaylov's departure, PM Borissov said: "It is unacceptable that Bulgaria - which is one of the most tolerant states in the world and where people of different ethnic and religious background peacefully live together - should be associated with racism."
UEFA ready to "wage war on racists"
In a statement issued on Tuesday, UEFA President Aleksander Ceferin urged governments to escalate the "war on the racists" to help football authorities eliminate it from stadiums, and blamed a "rise of nationalism" for encouraging abuse.
"Believe me, UEFA is committed to doing everything it can to eliminate this disease from football," Ceferin said. "We cannot afford to be content with this. We must always strive to strengthen our resolve.
"More broadly, the football family - everyone from administrators to players, coaches and fans - needs to work with governments and NGOs (non-governmental organisations) to wage war on the racists and to marginalise their abhorrent views to the fringes of society.
"There were times, not long ago, when the football family thought that the scourge of racism was a distant memory. The last couple of years have taught us that such thinking was, at best, complacent.
"The rise of nationalism across the continent has fuelled some unacceptable behaviour and some have taken it upon themselves to think that a football crowd is the right place to give voice to their appalling views."
Prime Minister Boris Johnson's Downing Street office called on UEFA to impose tough penalties on Bulgaria. Ceferin sees eradicating racism as part of a wider effort.
"Football associations themselves cannot solve this problem," Ceferin said. "Governments too need to do more in this area. Only by working together in the name of decency and honour will we make progress.
"As a governing body, I know we are not going to win any popularity contests, but some of the views expressed about UEFA's approach to fighting racism have been a long way off the mark."
FIFA: No place for discrimination in football
World governing body FIFA has also issued a statement condemning the incidents that took place in Sofia and urged all its member associations to take a zero-tolerance to racism.
"FIFA's position on the issue of discrimination is unequivocal: discrimination of any kind has no place in football.
"FIFA condemns in the strongest terms last night's incidents at the Bulgaria vs England match.
"FIFA urges all member associations, leagues, clubs and disciplinary bodies to adopt similar procedures as FIFA, as well as a zero-tolerance approach to incidents of racism in football, and to apply harsh sanctions for any such kind of behaviour.
"Furthermore, FIFA has been supporting its member associations over the past years through the FIFA Good Practice Guide on Diversity and Anti-Discrimination, in order to help them foster diversity and anti-discrimination in their territories."
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'UEFA sanctions among the toughest'
UEFA has had a three-step process in place for a decade to deal with racism at matches.
The first step was enforced during the first break in Sofia, with the public announcer warning that the match could be called off completely unless the racist abuse stopped. During the second break, dozens of Bulgaria fans involved in the chanting, many of them wearing dark hoodies, left the stadium. England players decided against not continuing playing.
"UEFA's sanctions are among the toughest in sport for clubs and associations whose supporters are racist at our matches," Ceferin said. "The minimum sanction is a partial closure of the stadium a move which costs the hosts at least hundreds of thousands in lost revenue and attaches a stigma to their supporters."
What evidence will UEFA look at?
UEFA's control, ethics and disciplinary body will consider the reports from the match referee, its match delegate and from 'spotters' in the crowd working for the Fare network, which works to stamp out discrimination and promote inclusion in the European game.
It will also look at evidence from other sources, such as television footage and CCTV. Football Association chairman Greg Clarke said on Monday night that security staff from his organisation would gather witness statements, and UEFA would also look at these if submitted.
"We believe events in Sofia last night should result in Bulgaria being kicked out of Euro 2020 by being denied any possible entry to the finals," Fare network executive director Piara Powar told the AP.
"The scale of the problems in evidence, the failure of the Bulgarian FA to take effective preventative measures, and the continuing denial from its leadership shows that this is a football structure that does not deserve to be competing with the elite in Europe.
"They should be held accountable. We believe the legal armoury and evidence is there for UEFA to move to their final sanctioning step."
What happens then?
The UEFA control, ethics and disciplinary body must decide whether to open an investigation based on the evidence presented to it. The body may wait until after the final group of Euro 2020 qualifiers of this international break is played on Tuesday night to look at evidence, but may move faster than that.
What punishment could Bulgaria face?
Under Article 14 of UEFA's disciplinary regulations which relate to racism, the punishment may be to order the Bulgarian Football Union to play one match behind closed doors and issue a 50,000 euros fine (which equates to just over £43,500).
However, there is provision under Article 14, 'where circumstances of the case require it' to impose additional disciplinary measures such as ground closure for multiple matches, forfeiture of a match, points deduction or disqualification from the competition.
FIFA look to enforce bans at worldwide level
FIFA president Gianni Infantino has called for "new, stronger and more effective ways to eradicate racism in football" in the wake of the abuse suffered by England players in Sofia.
Infantino said in a statement: "I call on all football governing bodies to join us and think together of new, stronger and more effective ways to eradicate racism in football.
"As a starting point, I suggest that all competition organisers enact regulations which envisage life bans from stadiums for those who are found guilty of racist behaviour at a football match. FIFA can then enforce such bans at a worldwide level."
A FIFA statement confirmed the proposal: "Following changes made to its disciplinary code in June 2019, FIFA may extend worldwide any sanctions that a confederation or member association imposes for racist incidents, such as those which occurred in Sofia during the UEFA EURO 2020 qualifier match between Bulgaria and England.
"FIFA therefore expects to be informed as soon as practicable regarding the relevant decisions of the UEFA disciplinary bodies in relation to this particular case. This would allow any sanctions imposed to be extended worldwide."