Qatar have emerged as strong contenders for the tournament despite having to face issues surrounding the heat, which averages more than 40 deg C in June and July and last summer topped 50 deg, and the small size of the country and population.

The Qatar bid have said air conditioning the stadiums can lower the temperatures into the low 30s, but the USA's Chuck Blazer, a long-standing member of the FIFA executive committee who will vote on the 2018 and 2022 hosts on December 2, does not believe this is enough.

Blazer told the Wall Street Journal: "You can air condition a stadium, but I don't see how you can air-condition an entire country."

The USA are bidding against Qatar along with Australia and outsiders South Korea and Japan.

The publication by FIFA tomorrow of the bid inspectors' evaluation reports is expected to provide further questions about the World Cup being staged in Qatar.

As well as the heat, the size of the country is an issue - it is half the size of Wales with a population of less than 1million, half of whom live in the country's only city of note, Doha.

A special meeting of the FIFA executive committee has been called on Friday in Zurich with only two items on the agenda: to discuss the evaluation reports and the outcome of the FIFA ethics committee hearing.

Some FIFA insiders believe there may be a move to bar Qatar from the bid process on technical grounds if the evaluation report raises too many high-risk problems.

Yesterday, the head of Qatar's bid insisted they were "now credible contenders".

Bid chief executive Hassan Al Thawadi told the Aspire4Sport conference in Doha: "Our enthusiasm for the sport rivals any other country on the planet.

"The weather posed many concerns but we acknowledged the issue and we continue to overcome this.

"The benefits of our bid have won over many sceptics."

FIFA's ethics committee will announce their findings on Thursday into separate investigations into corruption and collusion claims.

Two FIFA executive committee members, Nigeria's Amos Adamu and Tahiti's Reynald Temarii, have been alleged by the Sunday Times to have asked for cash for projects in exchange for votes.

Other low-ranking FIFA officials also face sanctions, and all deny any wrongdoing.

The collusion allegation is that Qatar and Spain/Portugal, who are bidding against England for 2018, have done a deal for votes in contravention of FIFA rules.