Support for Sepp Blatter extending his 17- year hold over global soccer weakened in the final hours before his re-election bid two days after criminal probes rocked the world’s most popular sport.

His longtime backers in the Caribbean said they may shift their support to his rival, Prince Ali Bin Al Hussein, as pressure grew following the investigations on two continents into soccer’s governing body. The U.S. and Canada also announced support for the Jordanian prince, while South American delegates said the group may not vote as a bloc.

“It will be a close call,” Michael van Praag, the Dutch soccer head who dropped out of the election race last week, said as he entered the FIFA congress. “There are more people who want a change than you might think. If I were him I would reconsider” his position even if he wins, he said.

FIFA’s 209 members will cast votes in a secret ballot later today in Zurich. Blatter has received the solid backing of confederations in Africa and Asia representing 100 votes. He needs the support of two-thirds of members present at the congress to win in the first round.

UEFA, the group that oversees soccer in Europe, had floated the idea of a boycott, before deciding to participate. Its chief, former French international Michel Platini, publicly urged Blatter to resign.

“The events of last Wednesday have unleashed a storm and it was even questioned that this congress would take place,” Blatter said in his opening remarks. “Today I am appealing to unity and the team spirit so that we can move forward together. We are here today to tackle the problems.”