The ex-PM (above) smokes one of his trademark cigars

It's impossible to think of Winston Churchill without a cigar.

Yet the makers of a new biopic of the wartime leader have still deemed it necessary to warn film-goers that ‘the depictions of tobacco smoking are based solely on artistic consideration’.

The ludicrous health alert comes in the final credits of Darkest Hour, in which Gary Oldman has been acclaimed by critics for his performance as the former Prime Minister.

The movie is already out in the US and will be released in Britain next month.

Churchill is rarely seen without a cigar in the film, set in 1940 when Britain stood alone against Hitler. In the opening scenes his face is lit in a darkened room by a cigar. He continues to puff away when he greets a five- month-old baby on the London Underground.

The movie is already out in the US and will be released in Britain next month

The secondhand smoke warning (above) which features in the film credits

Leading historians last night ridiculed the warning.

Professor Mary Beard said: ‘It only adds to the temptation if you ask me.’

Biographer Hugo Vickers said: ‘Perhaps they should have added a line, “Sir Winston Churchill lived to be 90.” ’ And Professor Sir Richard Evans, an expert in European history, said: ‘I don’t suppose the film will prompt many to rush out and buy cigars.’

Universal Pictures, which is distributing the film in the UK, declined to comment.