The joint North American bid of Canada, Mexico and the U.S. is the favourite to win when the member associations of world football's governing body, FIFA, vote at its Congress in Moscow on June 14 a day before the opening game of this year's tournament.
But Morocco are feisty rivals and, despite cracks in their own voting bloc, are expected to make a credible challenge.
Their African support base, a potential 54 votes out of a total of 211, has been a primary focus for both bids over the last few days as what was presumed to be a solid bloc behind Morocco is now looking less guaranteed.
Liberia has already said it would vote for the "United bid" and South Africa’s government warned its football association not to vote for Morocco, with whom it has strained relations.
Morocco sent its bid chief Hicham El Amrani to Johannesburg last week to meet regional FA presidents, and the Americans, who have former FIFA competitions director Jim Brown running their bid, will do so this weekend, attempting to persuade wavering voters to get behind them.
Also vital to the process is the bid evaluation report that FIFA is due to publish before the Congress, possibly over the next few days.
In April it sent evaluators to Mexico City, Atlanta, Toronto and New York and then straight on to four of Morocco’s proposed venues.
Previous bid inspections were seen as symbolic but revised bidding rules allow for the evaluation team to disqualify a candidate before the ballot even takes place.
This is because the 2026 finals will comprise 48 teams for the first time, severely testing the capacity of a host.
This is the strong point of the joint North American bid with 23 venues which they claim will help FIFA achieve new records for attendance and revenue, increasingly vital for a world governing body that have been feeling a financial pinch.
Morocco’s bid plays heavily on the country’s passion for football and its fan culture, relatively compact size, proximity to Europe, climate and the emotional appeal of holding only the second tournament on the continent after 2010 in South Africa.
Morocco has already made unsuccessful bids to host the finals in 1994, 1998, 2006 and 2010, although it was close on three occasions.
The country was second to the U.S. for 1994, behind France for 1998 and just lost out to South Africa for the 2010 finals.
Mexico has twice previously hosted the World Cup - in 1970 and 1986 - and the U.S. in 1994. It would be a first for Canada.