It is perhaps the most famous peroration of the second world war. “We shall fight on the beaches, we shall fight on the landing grounds, we shall fight in the fields and in the streets, we shall fight in the hills; we shall never surrender,” declared Winston Churchill.

However, if his earlier thinking on the subject was anything to go by, Churchill should have added the rejoinder: women will be allowed to do so only if they are dressed as men. A long-neglected essay by Britain’s wartime leader, written a year before war with Germany was declared and explored in a new book, reveals that Churchill held bizarre views on the role of women in conflict.

The essay, published in the monthly Strand Magazine and entitled Women in War, opens with the arresting observation: “The idea of women entering the line of battle and fighting in war is revolting to us. The whole civilisation of the western world is based upon the traditions of chivalry which have come down from medieval times and still exert a potent force.” Invoking the Christian canon and Greek philosophers, Churchill, who was then a backbench MP, suggested there could, however, be exceptions. “We are not revolted particularly by the idea of women fighting disguised as men,” he wrote. And he continues: “Some women are very like men, and a woman disguised as a man does not challenge the principle of women fighting.”

Churchill’s comments are light years away from those of the modern British army, which last week launched a new recruitment campaign aimed at reaching people who have historically not been attracted to a military career.

General Sir Nick Carter, chief of the general staff, explained: “Our traditional cohort would have been white, male, Caucasian 16 to 25-year-olds, and there are not as many of those around as there once were. Our society is changing, and I think it’s entirely appropriate for us therefore to reach out to a much broader base to get the talent we need to stay in that combat effectiveness.”

Professor Richard Toye, head of history at the University of Exeter, and a leading expert on Churchill, came across the essay while researching for a chapter he contributed to a new book, Rethinking Right-Wing Women. “It wasn’t something Churchill was obsessed with making a point,” Toye said. “He rather kept his views about women under his hat.”

Rather, Toye suggested, Churchill, who would go on to win the Nobel prize for literature, was doing the bidding of his literary agent, Emery Reves who would suggest topics for the politician to write about. “Churchill didn’t do stuff unless he was being pretty well paid,” Toye said. “Strand Magazine’s ability to pay him what would probably have been several hundred pounds in those days indicates this was a commercially successful magazine.”

In his essay, Churchill suggested that even the Germans had “set their faces like flint against using women as fighters. They hold to the broad human principle that the women’s place is in the home and that the male protects her.” But, despite feminist ideas gaining “a great ascendancy” in England, he suggested “the tests of war would very soon show that the stronger sex would have to do the fighting and the weaker the suffering and weeping”.

Toye suggested Churchill’s views were relatively unusual for the time. “He was fundamentally fairly sexist but, unlike a lot of other politicians at the time, he didn’t tend to offer generalisations about women’s capacities. He was somebody who was at best a lukewarm supporter of votes for women. He’d resisted the extension of the franchise in 1928 but in spite of that he generally didn’t say ‘we mustn’t give women the vote because their brains aren’t right or they lack physical capacity’, it was more ‘I don’t see that the demand is there, that this will not be beneficial to our party electorally’.”

The transformative power of technology was a particular concern, given how it could create a level playing field for the sexes. “The women, at great disadvantage with club or spear, will, it is said, be on equal terms in pressing the button of a machine-gun or in pulling a trigger,” Churchill wrote. But that did not mean women should participate in aerial conflict. “Only at the very last gasp of our life and civilisation should we allow women fight in the air,” Churchill concluded.

While the tone of the piece is undoubtedly Churchillian, the extent to which it is all his own work remains opaque. He employed ghostwriters and an army of researchers to help craft his words – words that continue to resonate as the fascination with Churchill, typified by the new film Darkest Hourcorrect starring Gary Oldman, shows no sign of abating. “He’s become the archetype for many people of what is successful political leadership,” Toye said. “He succeeded in rising above party, at least during the war itself -so he can be seen as a non-partisan figure.”