Read this and answer the question. If the question is unanswerable, say "unanswerable".

The government collapsed after only nine months when the Liberals voted for a Select Committee inquiry into the Campbell Case, a vote which MacDonald had declared to be a vote of confidence. The ensuing 1924 general election saw the publication, four days before polling day, of the Zinoviev letter, in which Moscow talked about a Communist revolution in Britain. The letter had little impact on the Labour vote—which held up. It was the collapse of the Liberal party that led to the Conservative landslide. The Conservatives were returned to power although Labour increased its vote from 30.7% to a third of the popular vote, most Conservative gains being at the expense of the Liberals. However many Labourites for years blamed their defeat on foul play (the Zinoviev Letter), thereby according to A. J. P. Taylor misunderstanding the political forces at work and delaying needed reforms in the party.

What had a big impact on the Labour vote?
unanswerable