A decision will be made in December on the hosting of the two tournaments when FIFA's powerful cabinet, its 24-man executive committee, chooses from a list of nine candidates.
It is the first time the hosting of two World Cups is being made at the same time and will come at the end of a fairly brief and low-profile campaign, enlivened only by English tabloid revelations and Australian accusations of alleged bribery.
England, despite the resignation of FA chairman Lord Triesman after a tabloid sting in which he accused rival bids of corruption, are the bookmakers' favourites to win the 2018 bid, ahead of rival European countries and the United States.
Russia is a strong outsider but joint bids from Belgium and Netherlands, plus Portugal and Spain, need to overcome FIFA's reluctance to have co-hosts again after what officials said was a difficult and costly event in South Korea and Japan in 2002.
Australia's football federation said on Tuesday it had issued proceeding against newspapers who alleged malpractice in their bid. Among the allegations were that the bid had given inappropriate gifts to FIFA officials and their wives.
But central to the chances of the nine bids will be the intense inspections FIFA will launch later this month, sending experts to pick over the candidate's bid books - voluminous documents that detail how they plan to host their World Cup.
Once the inspections are completed by September, FIFA's executive committee will receive a summation of the best bids but it is not always the most suitable candidate that wins.
