A bizarre plan to relocate the entire population of Hong Kong to Northern Ireland was considered an option in the uncertain years before Britain handed back the former British colony to Chinese rule, formerly classified government files showed.

Britain's National Archives on Friday released a 1983 government file called "Replantation of Northern Ireland from Hong Kong," which showed British officials discussing a far-fetched proposal to settle 5.5 million Hong Kong people in a newly built "city state" between Coleraine and Londonderry.

George Fergusson, an official at the Northern Ireland office, was inspired by a university lecturer's proposal to "transplant" Hong Kong to Northern Ireland — a move that would supposedly revitalize the local economy as well as save Hong Kong, which the lecturer believed had "no future on its present site."

"At this stage we see real advantages in taking the proposal seriously," Fergusson wrote in a memo to a colleague in the Foreign Office.

While it wasn't clear if Fergusson was writing tongue-in-cheek, the droll reply he received showed that it wasn't taken seriously.

"My initial reaction ... is that the proposal could be useful to the extent that the arrival of 5.5 million Chinese in Northern Ireland may induce the indigenous peoples to forsake their homeland for a future elsewhere," quipped David Snoxell at the Republic of Ireland Department. "We should not underestimate the danger of this taking the form of a mass exodus of boat refugees in the direction of South East Asia."

An official scribbled in the margins: "My mind will be boggling for the rest of the day."

Though outlandish, the idea illustrated anxieties at the time about the future of Hong Kong. Prime Minister Margaret Thatcher began talks with China on the topic in 1982. Two years later, the two sides agreed that the city would return to Chinese rule in 1997.