Chancellor Gordon Brown had already insisted the government would support any bid by England to host the tournament, though Blatter has warned that the tournament could go to either North America or Asia.
"The executive committee must take a decision whether the rotation should include all the confederations in which case the 2018 World Cup should be in CONCACAF (North and Central America)," he explained.
"They cold also decide that the Americas should be considered as one and then rotation would go to Asia.
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"It may also be that the majority of the FIFA executive committee where you have eight European representatives can find the 13 votes needed [from the total of 24, to bring the World Cup back to Europe]."
The FIFA executive committee is to meet in December to decide whether the rotation policy, of which Blatter is a proponent, should continue, or whether each tournament should be open to all bidders.
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