Sepp Blatter is to resign as president of football’s governing body Fifa amid a corruption scandal and is reportedly under investigation in the US.
In announcing his exit, the 79-year-old Swiss has called an extraordinary Fifa congress “as soon as possible” to elect a new president.
Blatter was re-elected last week, despite seven top Fifa officials being arrested two days before the vote.
But he said: “My mandate does not appear to be supported by everybody.”
When will a new president be elected?
Blatter, who has been Fifa president since 1998, said: “The next ordinary Fifa congress will take place on 13 May, 2016 in Mexico City.
“This would create unnecessary delay and I will urge the executive committee to organise an extraordinary congress for the election of my successor at the earliest opportunity.
“This will need to be done in line with Fifa’s statutes and we must allow enough time for the best candidates to present themselves and to campaign.”
The extraordinary congress is expected to take place between December 2015 and March 2016.
Who wants to be the next Fifa president?
Sepp Blatter beat Prince Ali bin al-Hussein of Jordan to earn a fifth term as Fifa president and his beaten opponent says he remains at the disposal of the national associations for the new Fifa election.
“I am always there to serve football and I think that’s the most important thing and to do so much work to fix this organisation in a proper way,” said Ali.
Former France international David Ginola wanted to stand but failed to meet the criteria to do so. His team have confirmed he also intends to stand as a candidate again.
Kieran Fox, BBC News, in Zurich
|“The invitation came at 4pm local. A scramble to Fifa HQ in the leafy hills of Zurich and still no more details. The news conference was due to start at 6pm, 6.30pm, then 6.45pm. The large conference room was barely a third full.
At 6.45pm a shrugging, forlorn director of communications walked in. Mr Blatter would be making a statement he said. Blatter looked reluctant, perhaps a little sad that 40 years of his life’s work was coming to an end. The press room was silent. No one really expected this just four days after winning a fifth term as Fifa president.
His speech lasted barely four minutes. Speech over, he left to silence.”
What are Blatter’s plans?
Fifa was rocked last week by the arrests on charges of racketeering, wire fraud and money laundering as part of a US prosecution that also indicted 14 people.
The latest allegations of corruption to emerge on Tuesday involved reports claiming Fifa general secretary Jerome Valcke was responsible for an alleged $10m (£6m) payment of bribes over South Africa’s bid to host the 2010 World Cup. He denies any wrongdoing.
A separate criminal investigation by Swiss authorities into how the 2018 and 2022 World Cups were allocated is also under way.
Blatter says he stood for re-election as he felt it was the “best option for football” but took his decision to resign in Fifa’s best interests.
“Since I shall not be a candidate, and am therefore now free from the constraints that elections inevitably impose, I shall be able to focus on driving far-reaching, fundamental reforms that transcend our previous efforts,” he said.
“For years, we have worked hard to put in place administrative reforms, but it is plain to me that while these must continue, they are not enough.
“The executive committee includes representatives of confederations over whom we have no control, but for whose actions Fifa is held responsible. We need deep-rooted structural change.”
“He’s not a man who wanted to go out this way – he wanted to remain as Fifa’s leader,” said BBC Radio 5 live sports news correspondent Richard Conway.
“He wanted to bring Fifa and football back together but that ignored the huge weight of the allegations that stood against the organisation.
“And, of course, that threat from the US Department of Justice that this was not the end, it was only the beginning of their enquiries.
“Jerome Valcke is under pressure in connection with a bribe that the US Department of Justice allege was paid from a Fifa account to Jack Warner, a former Fifa executive. That is exactly where this story is going to be going in the next few weeks and months.
“In the end, Blatter’s position became untenable and we will perhaps know more in the weeks ahead about what exactly tipped him over the edge.”
Daughter “sad and relieved”
Blatter’s daughter Corinne told the BBC that the pressure “had been wearing him down.”
“I am both sad and relieved,” she said. “My wish now is for calm to be restored, both for my father and for world football. But above all I wish for the world to finally acknowledge the great things he has done for football in the last 40 years.
“My father is my father. He is a wonderful person. By making this decision, he also wants to protect us, his family, first and foremost. His decision has nothing, absolutely nothing at all, to do with the accusations that are currently circulating. My father is an honest person who has dedicated his life to football.”
How has the football world reacted?
Michel Platini, the president of European football’s governing body Uefa, had urged Blatter not to stand for re-election and to quit following the arrests in Switzerland.
After Blatter stated his intention to step down, Platini said: “It was a difficult decision, a brave decision, and the right decision.”
The Football Association has been vociferous in its criticism of Blatter.
“This is great news for football. It should have happened years ago,” FA chairman Greg Dyke told the BBC.
“The timetable doesn’t matter. There has to be a root-and-branch investigation of Fifa. It has all got to be transparent in the future.”
Former Portugal international Luis Figowithdrew from the presidential election eight days before the vote.
“A good day for Fifa and for football,” he said. “Change is finally coming.
“Now we should, responsibly and calmly, find a consensual solution worldwide in order to start a new era of dynamism, transparency and democracy in Fifa.”
Meanwhile, World Cup sponsor Coca-Cola has called Blatter’s resignation “a positive step”.
“We believe this decision will help Fifa transform itself rapidly into a much-needed 21st century structure and institution,” said a statement.
What of the 2018 and 2022 World Cups?
England lost out to Russia in the bidding for the 2018 World Cup and Simon Johnson, who led England’s bid , told BBC 5 live: “I want the full facts around the bidding to be known and published. I want there to be openness and transparency.
“If everybody won it because of a fair fight and everything was fair and objective and transparent then good, well done.
“If it wasn’t, if it was found there was improper behaviour in any way by any of the winning bidders then Fifa must have a look at whether they should re-open the process.
“I think 2018 will go ahead in Russia. The preliminary draw for the Russia World Cup is a few weeks away and it’s too late to change that, but 2022 in Qatar is another matter.”
Dyke added: “We can go back to these two World Cups. If I was in Qatar now I would not be very confident.”
But Sheikh Hamad bin Khalifa Al Thani, president of the Qatar Football Association, issued a strong response.
“We would urge Mr Dyke to let the legal process take its course and concentrate on delivering his promise to build an England team capable of winning the 2022 Fifa World Cup in Qatar,” he said.