Less than half of listed firms outside of the biggest 350 companies have met targets for women in the boardroom and a “shocking” 54% still have no female top bosses, new research has revealed.

A report by Women on Boards UK showed that while solid progress has been made within the UK’s top 100 and 250 listed companies, diversity is still woefully behind in the wider FTSE All-Share.

Its study of the 261 firms outside of the FTSE 350 – with a combined stock market value of £63 billion – found that just 48% have met the UK goal for at least a third of board roles to be held by women.

This compares with nearly two thirds – 65% – of firms in the FTSE 350.

To accelerate diversity, and close the gender pay gap, we must look beyond the FTSE 350 and ensure that every company in the FTSE All-Share is held accountable to change

It also revealed that 37% – 98 – of the FTSE All-Share, excluding 350 company boards, have only one or no female directors.

And more than half of firms still have all-male executive leadership teams against just 8% in the FTSE 350 – branded “shocking” and “alarming” by Women on Boards UK.

Only 7% have female chief executives and 16% have chairwomen, the report found.

The findings follow the recent final report from the Hampton-Alexander Review, which concluded in February that its target had been met, with 34.3% of FTSE 350 board roles now held by women, up from 21.9% in October 2015.

But Fiona Hathorn, co-founder and chief executive of Women on Boards UK, said the job was “far from done”.

She cautioned that targets focusing on the FTSE 350 mask the fact that many companies have made little or no change and called for goals to be widened out across the FTSE.

She said: “While progress has been made over the past several years, much of this has been driven by the largest companies.

“There are many smaller listed companies who, with a collective market capitalisation value of £63 billion, have a significant impact on the UK economy.”

The research also revealed that only 3% of board members in the FTSE All-Share outside of the 350 are “directors of colour” and they are distributed across just 16% of companies.

“To accelerate diversity, and close the gender pay gap, we must look beyond the FTSE 350 and ensure that every company in the FTSE All-Share is held accountable to change.”

The Women on Boards UK report also revealed a worrying gender pay cap, at 20.2% on average across the FTSE 350 and 17% for the remainder of the FTSE All-Share – both higher than the 13.7% national average.

“While there are companies in the FTSE All-Share working hard to close their gender pay gap, many more companies need to seriously up their game on equal pay, said Ms Hathorn.

She is pressing for continued scrutiny of diversity in the FTSE All-Share and wants the goals to now go further, with a target for at least 40% of board roles to be held by women.

Women on Boards UK also wants all listed companies to report their gender pay gap, on a comply or explain basis.

A government spokesman said: “While we have seen huge improvements at the top of British business in recent years, there is still distance left to travel.

“We would encourage businesses to keep challenging themselves to progress towards more diverse workplaces.”