Prime Minister Maragert Thatcher chats to Soviet leader Mikhail Gorbachev, left, and his wife Raisa before lunch at 10 Downing Street in 1989

When Soviet leader Mikhail Gorbachev's wife boasted over an official dinner at Chequers that her country had 300 recipes for cooking potatoes, it seems Agriculture Minister Michael Jopling had his doubts.

Official files released by the National Archives show that Raisa Gorbachev was so keen to prove her point during the couple's visit in December 1984 that she even offered to send the minister a recipe book.

Seven months later, the promised volume duly arrived at the Ministry for Agriculture.

An accompanying note from Mrs Gorbachev declared triumphantly: "My apologies for being somewhat inaccurate: in fact, there are 500, rather than 300, recipes to cook potatoes."

Officials were at a loss to know what to do with it. One wrote to the Foreign Office: "It is, naturally, in Russian. If you have anyone who reads Russian and has a fondness for potatoes, we would be happy to lend it."

PA Media