The head of controversial religious movement the Moonies has arrived in the UK for the first time in 10 years and is due to speak at a London event.
Mr Moon fought a libel case over brainwashing allegations
The Reverend Sun Myung Moon, 86, was excluded from Britain a decade ago over concerns about methods of recruitment to his Unification Church.
The Home Office said it had lifted the exclusion order as Mr Moon did not pose a threat to public order.
The Moonies are best known for their mass weddings of thousands of couples.
There have also been claims that the church has used inappropriate methods to recruit new members.
Mr Moon, who at one point had up to 500,000 followers, has always strenuously denied these claims.
The event on Saturday night is part of a tour of world cities to launch a new global body for the resolution of conflict called the Universal Peace Federation.
An estimated 1,300 people are expected to attend.
Moonies are perhaps best known for their mass weddings
Home Secretary Charles Clarke said in an interview with the Daily Telegraph that he had wanted to exclude Mr Moon but "there was not a good enough reason".
But the Home Office said: "We keep exclusions under review. The Unification Church in the UK is extremely small and any visit by its founder is considered unlikely to pose any threat to the public order of this country."
Mr Moon was initially banned by Conservative former Home Secretary Michael Howard in 1995 amid concerns "his presence would not be conducive to the public good".
Two years ago, the then Home Secretary David Blunkett also refused Mr Moon entry to the UK.