Nearly half of all major British companies have failed to reduce their gender pay gap over the last year, data released on Friday showed, despite rising government pressure and public scrutiny.

Britain’s women’s minister said there was a need for a “cultural change” after publication of the data under a new government requirement for companies and charities with more than 250 employees to report their gender pay gap every year.

About 4,000 of the 8,424 private companies that reported their data by Thursday’s deadline showed pay gaps that had either widened or remained the same, according to figures released by the Government Equalities Office.

“Actions to tackle the gender pay gap are good for business. We recognise that in order to close the gap entirely we still need a much wider cultural change,” said Britain’s Minister for Women and Equalities Penny Mordaunt.

Pay disparities in Britain have come under the spotlight since the government forced employers to submit gender pay gap figures annually from last year.

Despite sex discrimination being outlawed in the 1970s, men in Britain earned on average 17.9 percent more than women last year, according to government data.

About 40 percent of companies reported narrower pay gaps than last year, while the remainder were not calculated because data for the previous year could not immediately be found for comparison.

The data shows the difference between average hourly male and female pay.

The government said about half of British companies had implemented plans to tackle their pay gap.

It said it had introduced measures like shared parental leave, and was spending about 6 billion pounds ($7.8 billion) on childcare support.

Hannah Peaker, chief of staff at Britain’s Women’s Equality Party, said more needed to be done – including changing the education system to help girls, investing in care and boosting the number of women in politics and business.

“There is no silver bullet here,” she said in a statement. “Pay gap reporting is just the beginning.”