A government-backed review has urged FTSE 350 companies to renew their commitment to diversity by extending a target to them of filling one third of their senior leadership positions below board level with women.
The number of women on company boards has more than doubled since 2011 according to the Hampton-Alexander Review 2017.
The specific target for FTSE 350 companies is that they fill one third of senior leadership positions below board level with women.
The review, chaired by Sir Philip Hampton and the late Dame Helen Alexander, revealed almost 28 per cent of board positions in FTSE 100 companies are occupied by women - up from 12.5 per cent in 2011.
In that time the number of all-male FTSE 350 company boards fell to eight from 152.
The review’s target for FTSE 100 companies is 33 per cent for women on boards by 2020.
For FTSE 350 companies to catch up at least 40 per cent of appointments to senior positions would have to be filled by women over the next three years.
Sir Philip, the chairman of GlaxoSmithKline, said: “Some of our largest companies have made significant progress towards meeting these challenging targets, both on boards and in their leadership teams.
“We should be seeing all FTSE companies now making strides to improve the gender balance at the top.
“This year we have seen progress pick up on FTSE 100 boards and go slow elsewhere.
“We must now renew commitment to this important issue for UK business to fully harness the under-utilised potential of the many talented women in the workplace.”
The government established the Business Diversity and Inclusion Group in February this year, to bring together business leaders and organisations to coordinate action to remove barriers in the workplace and introduced mandatory reporting of gender pay gaps in April for voluntary, public and private sector employers with 250 staff or more.
The review found the best performer in the FTSE 100 was Next, where 47 per cent of its senior leadership is female, followed by Marks & Spencer which has 43.2 per cent.
Among the all-male executive committees, seven were in the FTSE 100 and included St James’s Place, Barclays and BP.
Justine Greening, education secretary and minister for women and equalities said: “Tackling inequality in the boardroom and ensuring more women get into senior leadership positions is not just good business sense, it is vital to our economy.
“It is great to see some of our top companies really stepping up to address gender imbalances on their boards. We are making progress, but there is still a long way to go.
“That is why we all need to do our bit to improve workplace equality. The government is continuing to work with business to help remove the barriers that can hold women back in their careers.
“This includes being one of the first countries in the world to require all large employers to publish their gender pay and bonus data.”