Britain was so concerned by Russian president Boris Yeltsin's heart attacks and drinking in 1995 that contingency plans were drawn up in case he died in office, declassified files showed on Tuesday.
After Yeltsin suffered a second heart attack, the Foreign Office drafted statements of condolence, fearing for his health amid the boozing, according to documents released from Britain's National Archives.
In a hectic round of diplomacy, Yeltsin had a summit with US president Bill Clinton in the town of Hyde Park north of New York, on October 23, 1995.
He was rushed to hospital in Moscow with heart trouble on October 26, for the second time in under four months.
A cable the same day from ambassador Andrew Wood in Moscow on Yeltsin's medical condition reported on his drinking in New York.
"He consumed wine and beer greedily at Hyde Park and regretted the absence of cognac," the British diplomat said.
"One of his aides took a glass of champagne away from him when the aide felt enough was enough, and he was alcoholically cheerful at his press conference with Clinton."
An accompanying message from Major's wife, Norma, to Naina Yeltsina said: "I know how much you worry about him. He has carried a heavy burden these past few years, much to the good of his country and of the world."