Combination file photograph of FIFA President Sepp Blatter addressing a news conference at the FIFA headquarters in Zurich, Switzerland June 2, 2015 and UEFA President Michel Platini (R) attending the 65th FIFA Congress in Zurich, Switzerland, May 29, 2015.  [Photo/Agencies]

The two favourites were both upbeat.

"I am feeling good and very positive. The support I am receiving fills me with confidence," Infantino told Reuters in an email while travelling between meetings.

A spokesman for his Bahraini rival said: "Sheikh Salman is very confident about tomorrow's vote."

FIFA was plunged into turmoil by the corruption scandal that broke last year, beginning with a dawn raid to arrest delegates at a Swiss luxury hotel.

Criminal investigations led by the United States and Switzerland have spanned dozens of countries, focusing largely on the awarding of lucrative broadcast and marketing rights to the world's most popular sport. They are also examining the process by which FIFA awarded the next two World Cups to Russia and Qatar.

Acting FIFA president Issa Hayatou appealed to FIFA members in what he called one of the most important weeks in the history of global football, urging them to support a package of reforms on governance. These include introducing term limits for top officials and requiring them to disclose their earnings.

"I urge each of you to support the reforms in full here this week, and then to implement them to their entirety at home," Hayatou said in an address aimed at the six confederations that run soccer around the world.

"This will send a strong message that we have listened and that we are taking the action necessary to give football the foundation, and protection, it needs for the future."