A panda missed out on a first class flight to Washington in Margaret Thatcher's Concorde after she refused to accommodate him in the back of the plane.
According to papers released by the National Archives, the former prime minister was asked by the president of the London Zoological Society if she could allow space for the animal on the flight to her first summit with US President Ronald Reagan in January 1981.
Desperate for a boost to the cash-strapped London Zoo and keen to loan the bear to Washington's Smithsonian Institution, Solly Zuckerman contacted No 10 as he felt the publicity stunt could have aided the US and UK's much-vaunted "special relationship".
At the time, Cabinet secretary Sir Robert Armstrong wrote: "Lord Zuckerman sees this as a signal demonstration of the special relationship and would be very happy to time the announcement of the loan or the delivery of the panda in any way that the prime minister thought would be most likely to benefit Anglo-American relations.
"He even suggested that the prime minister might like to take the panda in the back of her Concorde, when she goes to Washington next month."
Mrs Thatcher turned down the proposal in a handwritten note, saying that Lord Zuckerman "knows more about pandas than I do" and should be able to "arrange these things" without her involvement.
Her private secretary, Clive Whitmore, replied: "She has commented that she is not taking a panda with her.
"Pandas and politicians are not happy omens!"
More from Margaret Thatcher
Giant pandas were once a star attraction at London Zoo, but it has not housed one since Ming Ming returned to her native China in 1994 following a three-year stay in the capital.
Edinburgh Zoo is now the sole home of giant pandas in the UK.