Andrew Jennings explains. Many in the 24 member executive council responsible for awarding the World Cup have been tainted by kickbacks and illegal ticket sales. Some were courted by England in their unsuccessful 2006 bid, giving the FA a bit of a black eye when the ISL investigations began.
The FA is in a tight spot because it is bidding for the 2018 World Cup and wants to do it without the suggestion of impropriety. But Sepp Blatter has transformed the FIFA into a giant pork barrel project where votes can be bought to award the World Cup. It's the usual order of business. The danger is that if the FA runs a clean as a whistle campaign, then it essentially takes it out of the running.