Less than 50 percent of American men would be "very comfortable" with a female head of government, according to a survey published on Tuesday that found men in Britain and the United States growing less comfortable with women in positions of power.

The Reykjavik Index for Leadership, launched in 2018 by a group of female politicians to look at attitudes toward women leaders in industry, government and other roles, found they had grown more negative in both countries in the past year.

In the United States, men's attitudes to female leaders in several areas of public life from politics to the judiciary grew more negative and just 49 percent of male respondents said they would be "very comfortable" with a woman as head of government.