The visit follows an announcement by Britain's Foreign Office last month that it has contacted Hezbollah's political wing in an attempt to reach out to its legislators. It said its ultimate aim is to encourage the militant group to abandon violence and play a constructive political role in the deeply divided country.
A Hezbollah statement issued Saturday says Hussein Hajj Hassan was invited by a number of British legislators to take part in a political meeting of parliamentarians to discuss "regional issues." It said he would be traveling to London on Sunday.
Britain's Foreign Office confirmed he has been granted a restricted validity, singly entry visa for the purpose of the visit.
A spokeswoman, speaking anonymously in line with government policy, said the decision "is consistent with the government's policy of exploring contacts with members of Hezbollah's political wing."
She added that there are no plans for official meetings with government ministers, only parliamentarians.
Hezbollah officials told The Associated Press last month that they welcomed talks with Britain but insisted the talks take place publicly. The Foreign Office denied at the time that it had pursued any secret talks with Hezbollah.
Britain ceased contact with the group in 2005 and listed its military wing as a terrorist organization last year. Hezbollah became part of a unity government in Lebanon in May after violent street clashes in which its gunmen and their allies briefly took over large parts of Beirut.