Britain's most powerful business leaders are calling for greater action on gender diversity and workplace sexism in the run-up to new pay gap reporting rules coming into force.

Boardrooms across the UK have been warned that they need to get tougher on gender inequality or face severe reputational consequences in the coming months.

From April, gender pay gap reporting will require all UK companies with at least 250 staff to publish the gap ­between male and female employees.

While the number of all-male boards has dropped in recent years, there are still very few women in top jobs, with more men named David, Steve or Stephen leading a FTSE 100 firm than there were female bosses in 2016.

Sir Roger Carr, chairman of BAE Systems, warned companies that ignored female workers “you do so at your peril”. Opportunities for women across British businesses have been limited for far too long, he said.

“A fair reward structure has risen to the surface – there is an awareness level that wasn’t there even a year ago,” he told The Sunday Telegraph. “It’s not a women’s issue, it’s about getting businesses equipped with the best possible roles – the talent pool of the country will then be harvested. At least half the talent is female in this world. If you ­ignore that you do so at your peril.”