Head of world football wants to see hard evidence of the corruption allegations, after the former head of the FA accused four executive committee members of seeking bribes
Under British parliamentary privilege, Triesman claimed that four Fifa executive committee members had asked for favours of various kinds in exchange for their votes.
Had those favours been granted, it could potentially have changed the fate of England's bid to host the 2018 World Cup.
In the event, England crashed out at the initial stage of the process after receiving only one vote, Russia eventually going on to win the bid to host the tournament.
Triesman's recent allegations have prompted Fifa to open an investigation into the matter, but now Blatter wants proof that the alleged requests for bribes did actually take place.
"Repeatedly it is always said there is some corruption here and there but I don’t understand why, last autumn - after the Sunday Times allegations and the evidence we had been given and we had started the big activity with the ethics committee - did the FA in London not give us all the matters they are giving now, months later?" he told Keir Radnedge of SportsFeatures.com.
"At that time it would have been very easy to put everything together. We dealt with that but now there are other allegations so we have opened an investigation.
"Now, however, I must say also thank you to the FA for helping us because we must have the evidence of the allegations from the former chairman of the FA and also from the newspaper. We have received letters but there is no evidence.
"There is a principle which says you are innocent until declared guilty but naturally it’s not a good image when we are heading for an election.
"So I have given [notice] – and we will do it - that these matters must be solved before Congress [on May 30 and June 1]. I will not open Congress without these matters having been solved; when there is an emergency matter then emergency decisions or actions must be taken. I am sure that we will do it before [Congress]. It’s a question of will."