Britain's biggest public companies have a long way to go when it comes to achieving gender equality in leadership, according to a new report.
The government-backed Hampton-Alexander Review in its latest report on gender and corporate leadership on Wednesday found that only six women held the top CEO position across the 100 biggest companies in the U.K.
Researchers analyzed data related to 23,000 leadership positions at 350 of the U.K.'s largest publicly-listed companies, also known as FTSE 350.
In 2016, the review set voluntary targets aimed at increasing the number of women in leadership positions at companies listed on London's FTSE 350 index. A key objective was for 33% of board members, executives and senior managers reporting directly to executive committees to be women by the end of 2020.
According to the analysis, the combined proportion of female executives and senior managers at FTSE 100 companies — the 100 most valuable firms on London's stock exchange — increased from 27% in 2018 to 28.6% this year.
Just 23% of executive committees in the 100 biggest firms were made up of women — that meant only 262 of the FTSE 100's 1,135 executives were female.
"Too few women are being appointed into senior leadership roles in the FTSE 100, with around two-thirds of all available roles still going to men," the report noted, with the data showing that 36% of all executive and management appointments went to female candidates this year.
"As a result too many companies remain well adrift from the 33% target," the report's authors said. "Unless the appointment rate of women is nearer 50% in the coming year — that is half of all available roles going to women and half going to men — the FTSE 100 will not achieve the target by the end of 2020."
Only 20 companies in the FTSE 100 had already reached that objective, the report said, while just 18 had the potential to achieve 33% female leadership by 2020. The remaining 61 firms had "some way to go," researchers said.
When analysing the 250 biggest firms on the London stock exchange, the picture was a little brighter, with the combined proportion of female executives and senior managers rising 3% between 2018 and 2019 to reach 27.9%. The appointment of women to these roles had risen 5% to 35% this year, the report said — but despite the increase, two-thirds of all roles were still being given to men.
The number of women in boardrooms was also analyzed, with researchers finding that less than one in three FTSE 100 board members were women.
Only 25 women held the position of chair across the U.K.'s 350 largest companies — in FTSE 100 companies, just 5 women held the role, the data showed.
Gwen Rhys, Founder of Women in the City — an organization promoting gender diversity in business — told CNBC Wednesday it was "disappointing" we were still not seeing significant numbers of women progress to senior leadership roles.
"Companies need to take a long, hard look at their recruitment processes, engineer out blatant bias, encourage women to apply for senior roles, and give them honest feedback and opportunities to develop the experience they lack," Rhys said.
Meanwhile Valerie Stead, director of the Academy for Gender, Work and Leadership at Lancaster University's Management School, told CNBC in an email Wednesday that a "complex mix of interconnected challenges" were preventing women's advancement into leadership roles.
"While organizations are becoming responsive to more visible barriers such as pay and family-friendly policies, our research reveals that less visible stereotypical assumptions and behaviors that become embedded in workplace cultures are equally important to address," she said.
"Organizational structures still operate to an 'ideal worker' model that values and rewards those who can commit to a traditional long-hours culture. One important question to ask is how can we develop more flexible workplace structures that can enable more inclusive and diverse leadership teams?"