Soccer:Under-fire FIFA president Sepp Blatter embroiled himself in a Twitter war-of-words with Rio Ferdinand over his comments about racism.

The Manchester United defender had condemned Blatter's remark that racism on the pitch was not a problem and that racist abuse between players should be settled by a handshake.

The comments stirred up a storm which has led to calls for Blatter to resign.

Ferdinand contacted Blatter's Twitter account directly, writing: "@SeppBlatter your comments on racism are so condescending its almost laughable. If fans shout racist chants but shake our hands is that ok?"

The England player also criticised FIFA's attempts to clarify Blatter's comments with a statement on their website underneath a picture of Blatter with South African minister Tokyo Sexwale, who was imprisoned on Robben Island during the apartheid era.

Ferdinand wrote: "Fifa clear up the blatter comments with a pic of him posing with a black man..I need the hand covering eyes symbol!!"

Blatter was stung into a response on Thursday and replied directly to Ferdinand saying: "The 'black man' as you call him has a name: Tokyo Sexwale. He has done tremendous work against racism and apartheid in Africa.

"We have done several joint activities to raise awareness on the struggle against racism in South Africa. FIFA has a long standing and proud record in the area of anti-discrimination which will continue."

But Blatter has drawn the ire of several other well known sports figures. UK Sports Minister Hugh Robertson and Professional Footballers' Association chief Gordon Taylor have led the calls for him to resign.

Ferdinand's sentiments have been echoed in Thursday morning's English newspapers, and Robertson believes it is now time for Blatter to step down.

"This is incredibly serious but it is part of a pattern of behaviour," Robertson told BBC Radio 5 Live.

Asked whether Blatter should go, Robertson said: "Yes. I can't see there's anything terribly new in this. We've been saying this for some time. Sepp Blatter will expect the English and the English press to pile in on him."

The Football Association's relationship with FIFA has been stormy for some time. England's failed World Cup bid followed on the heels of a raft of corruption allegations against FIFA made by sections of the English press.

Although a number of FIFA executives have been found guilty of wrongdoing, the relationship remains fractious, while England's national governing body chose to abstain from the vote at Blatter's unopposed re-election earlier this year.

Taylor was equally critical of Blatter and hopes it leads to the Swiss' removal from power. He told Sky News: "He is the leader of world football, he has to be a leader in anti-racism.

"Racism is divisive and for him to say the player on the receiving end should forget about it at the end of the game and shake hands...we are going backwards...it is not good enough, it's embarrassing.

"And coming on top of his comments which were offensive about female footballers, his homophobic comments about homosexuals not going to Qatar, the World Cup bidding process, he won't have technology over goalline decisions and the corruption which is so plainly evident at FIFA. It is time for him to go.

"He has presided over a lot of issues which haven't been good enough. If he is the leader of world football I am not going to be a follower and I can't believe anyone could follow him.

"It can't be acceptable and I believe it is the straw which broke the camel's back. He should step aside so we can see what Michel Platini can do."

Former Sheffield Wednesday and Crystal Palace striker Mark Bright criticised Blatter for his "archaic" comments.

He told Radio 5 Live: "This is what Blatter is saying: at Hackney Marshes on Sunday morning you can say whatever you want to your opponent - whatever race, creed or colour he is - and at the end of the game when you shake hands it should be all forgotten - go to the bar and have a drink. Those days are over.

"It would be carnage at every football park across Britain where any ethnic playing in one team against a white person on another team, and (if a player) can say whatever he wants and say 'it's just part of the game'.

"It's an old-fashioned view, it's archaic, it's illegal."

Bright added that he did not expect Blatter to stand down from his position, but expressed hope that some of FIFA's corporate backers might be able to exert pressure.

"Will he resign? No he won't. Will he go? Only if the ripple-effect takes place, where you've got major sponsors of the World Cup thinking of withdrawing their sponsorship," he said.

"That then would be when FIFA would say they have to act and act quickly."

Preston defender Clarke Carlisle, the PFA chairman and a Kick It Out ambassador, warned that Blatter's comments run the risk of undermining years of work aimed at eradicating racism from the game.

"We've come through some 20 or 30 years of campaigning to bring racism to the height of awareness that it is at the moment," he told Radio 5 Live.

"To come so far on such a sensitive topic, [yet] in one fell swoop he can almost give carte blanche that racism is acceptable between the hours of 3pm and 4.45pm on a Saturday."

Stoke boss Tony Pulis felt Blatter had shown himself to be "miles away from reality" but wonders how, if at all, he will be held accountable.

Pulis said: "I think one thing it proves is that he is miles away from what is actually happening in football and in the world."I'm amazed that he has come out with the comments, but the big question is who is actually going to take him to task?

"I've heard Gordon Taylor saying he should resign, but who is above Blatter - is he all powerful and almighty?"

Wigan boss Roberto Martinez offered a slightly different view, claiming racism was not evident in the game and that a "cultural aspect" needed to be taken into consideration.

The Spaniard said: "When there have been a few problems probably it is because comments that people understood as racist, when probably they are not. The cultural aspect plays a big part in that.

"But I don't think there is racism in the game - at least from the experiences we have experienced."

Britain's FIFA vice-president Jim Boyce said he had been surprised by Blatter's remarks but stressed both FIFA and UEFA had done much to combat racism in football.

Boyce said: "I was very surprised to hear the president's remarks but have been pleased that both he and FIFA have come out to try to clarify the situation.

"Personally I believe there should be zero tolerance regarding racism, sectarianism and discrimination in any shape or form and I do know that many people at both FIFA and UEFA are working to eradicate this cancer from the game."