Football's major sponsors, Adidas, Sony and Visa, are calling on the game's governing body to deal thoroughly with allegations of corruption and bribery surrounding countries' bids for the World Cup.
With just days before the showpiece event kicks off in Brazil, Fifa is on the defensive, conducting an internal investigation into the decisions to hold the 2018 World Cup in Russia and the 2022 Cup in Qatar. Both countries have denied any wrongdoing.
Britain's Sunday Times newspaper alleges a former Fifa executive from Qatar, Mohammed Bin Hammam, used his influence to arrange deals and favours to win support for his country's bid. The paper has printed what it says are leaked documents showing bribes were paid to secure the event for Qatar, which Qatar denies.
Qatar's bid in particular has attracted controversy from the outset because of the extreme summer heat during the months when the Cup is played and the tiny country's lack of domestic soccer tradition, Reuters reports.
If it goes ahead, the tournament is expected to be switched to a date later in the year, creating scheduling headaches for broadcasters and European club soccer clubs.
The signs of unease from some of FIFA's paymasters will raise pressure on the organisation to take a firm line on Qatar and underlying concerns about how it is run.
"The negative tenor of the public debate around FIFA at the moment is neither good for football nor for FIFA and its partners," said German sportswear company Adidas, which has signed up as FIFA sponsor until 2030.
Japanese consumer goods company Sony said it expected the allegations to be "investigated appropriately".
Former US prosecutor Michael Garcia, leading Fifa's internal investigation, is due to report in July, about a week after this year's World Cup final.