The proportion of women high earners in business has remained static for the past five years, a study shows.
Women accounted for just over a quarter of higher rate taxpayers, or 1.26 million, said law firm Clyde & Co.
The percentage of female high earners in the UK has not changed for five years even though the total number of higher rate taxpayers has increased by over one million, said the report.
Heidi Watson, employment partner at Clyde & Co, said: "It is clear that the initiatives launched so far have not had an impact on national figures for women in high earning positions, which in turn impacts on the national gender pay gap. The Government will be hoping that the new gender pay reporting rules can change that."
A Government spokesperson said: "You can't have true opportunity without equality and that's why eliminating the gender pay gap is a key priority for this government.
"We are committed to supporting women at all stages of their careers to ensure that they stay in the workforce and progress to the most senior roles.
"The overall gender pay gap is the lowest on record at 19.2%, but we are clear that closing the gap is essential for improving the UK economy.
"We want to see it eliminated in a generation, which is why we will be requiring organisations to publish details of their gender pay gap.
"Greater transparency will shine a light on workplace practices and create the pressure needed to drive change."