The Zinoviev letter

The Zinoviev letter
	FALSE
	"A secret letter from Grigory Zinoviev, head of the Communist International in Moscow, instructed British Communists to stir up revolution, including sedition in the armed forces, and showed that a Labour government was serving Soviet interests."
Domain	Politics & Elections
Tactic	Fabrication; Imposture;
Era	Historical
First seen	1924
Origin	A document published by the Daily Mail on October 25, 1924, four days before a British general election
Last reviewed	2026-10-27
	Further reading: books on Politics & Elections

The Zinoviev letter was a document published in Britain four days before the general election of October 29, 1924. It purported to be a directive from Grigory Zinoviev, president of the Communist International, urging the Communist Party of Great Britain to prepare for revolution, including by agitating within the armed forces. Its publication embarrassed the minority Labour government of Ramsay MacDonald, which had recently signed treaties with the Soviet Union, and contributed to a Conservative landslide. The Soviet government denounced the letter as a forgery at the time. A 1999 study commissioned by the British Foreign Office concluded that it was almost certainly forged and that it had been leaked to the press with help from people connected to the intelligence services and the Conservative Party.

The claim

The letter, dated September 15, 1924, called for pressure on Parliament to ratify the Anglo-Soviet treaties, for the formation of Communist cells in the army and navy, and for preparation for armed struggle. Its implication was that the Labour government's policy of engagement with the Soviet Union served Moscow's revolutionary aims.

Origin

The British Secret Intelligence Service (MI6) obtained a copy of the letter in October 1924 and circulated it within government. The Foreign Office drafted a formal protest to the Soviet government. On October 25 the Daily Mail published the letter under dramatic headlines describing a Communist plot, and the Foreign Office released its protest the same day. MacDonald, who was both prime minister and foreign secretary, struggled to respond in the final days of the campaign.

What the evidence shows

Soviet denial. The Soviet government and Zinoviev immediately said the letter was a forgery. The original was never produced; only copies existed.
Inconsistencies. Analysts noted errors in the letter's titles, wording and format that were inconsistent with genuine Comintern documents.
The 1999 Bennett report. At the request of Foreign Secretary Robin Cook, the Foreign Office's chief historian, Gill Bennett, examined British and Russian archives. Her report concluded that the letter was almost certainly a forgery, probably produced by anti-Bolshevik Russian émigrés, and that MI6 officers had treated it as genuine without adequate checks. She found that individuals with intelligence connections had passed copies to the Conservative Party and to the press, though she found no evidence of an organized conspiracy by the intelligence services as an institution.

Consequences

The Conservatives under Stanley Baldwin won a large majority. Historians debate how much the letter affected the result; Labour's share of the vote actually rose, and the main loser was the Liberal Party. But the episode fueled a lasting belief within the Labour Party that it had been the victim of a dirty trick, and it soured British–Soviet relations. The Anglo-Soviet treaties were not ratified.

Why it persists

The Zinoviev letter is often cited as an early example of an "October surprise," a damaging revelation timed just before an election to leave no time for verification or rebuttal. It also illustrates how forged documents can be laundered through official channels and respected newspapers, gaining credibility at each step.

Lessons for readers

Be cautious of sensational documents released days before an election.
Ask whether an original document exists and whether it has been authenticated.
Official handling of a document does not prove it is genuine.
Consider who benefits from a leak and how it reached the press.
Investigations decades later can overturn accepted versions of events.

Sources

Gill Bennett, "A most extraordinary and mysterious business": The Zinoviev Letter of 1924 (Foreign and Commonwealth Office, 1999).
Gill Bennett, The Zinoviev Letter: The Conspiracy that Never Dies (Oxford University Press, 2018).
"Civil War Plot by Socialists' Masters," Daily Mail, October 25, 1924.