A quarter of all lawmakers serving in national parliaments worldwide are women, the International Parliamentary Union said Friday, warning though that progress towards gender parity was slowing amid significant "pushback".

In 2019, women accounted for 24.9 percent of parliamentarians worldwide, the IPU, which was founded in 1889 and is one of the world's oldest international organisations, said in a fresh report.

"There has been considerable progress" in recent years, IPU Secretary-General Martin Chungong told reporters in Geneva, pointing out that the percentage back in 1995 stood at just 11.3 percent.

"There has been a shift in the way people think," he said, pointing out that a quarter century ago the ambition was to get women to the 30-percent mark, while today "the idea of having 50-50 in parliament is the norm."

Four countries have reached full gender parity: Rwanda, Cuba, Bolivia and the United Arab Emirates.

Today, the Americas has the best gender balance in parliament, counting 31.3 percent women MPs across the region, ahead of Europe which counts just under 30 percent.

The Pacific has the worst record on female representation in parliament, with only 19.4 percent, and three countries in this region -- Micronesia, Papua New Guinea and Vanuatu -- have no women members of parliament at all.

Chungong warned that worldwide there was now clearly "a slowdown in the growth of women's parliamentary participation." 

Last year, women's global representation in parliament grew by only 0.6 percent, after an already modest increase of 0.9 percent a year earlier.

"There seems to be pushback when it comes to women's political participation, and it is important that we push back against pushback," he said.

The IPU, a grouping of 178 legislative chambers that seeks to improve representative democracy worldwide, urged nations to redouble efforts towards gender parity by using tactics including carefully designed quotas. 

Chungong said there were several trends that gave rise to optimism, including the #MeToo movement against sexual misconduct.

That movement, he said, "has the potential to help boost women's political representation, given the fact that one of the inhibiting factors for women political participation is sexism, sexual harassment, gender-based violence."

"The #Metoo movement has brought these issues to the fore."

"It is important then that we seize this potential, this momentum to continue to work ... to increase the base of women's political representation," he said.

"Otherwise it will take more than a century ... to achieve gender equality."