The huge outcry in Spain over football federation chief Luis Rubiales' forcible kiss of World Cup player Jenni Hermoso highlights the waning power of male chauvinism in a country that has become a benchmark for feminism, experts say.

Prosecutors are investigating Rubiales over the kiss he planted on Hermoso's lips during the medal ceremony after Spain won the Women's World Cup final in Australia on August 20 but the 46-year-old has refused to resign over what he has defended as a "little peck".

But Hermoso has said "at no time" did she consent to the kiss, saying it made her "feel vulnerable and the victim of an assault".

Ines Alberdi, a Spanish sociologist who specialises in women's rights, said Rubiales' speech in which he refused to resign was "incredible", and showed how "he doesn't realise at all" the seriousness of his actions.

"What he was effectively saying in his speech was: 'Look, I didn't rape her'," Alberdi, the former executive director of  the UN Development Fund for Women, told AFP, describing the now-suspended football chief as an "old school male chauvinist".

Hundreds of protesters gathered in Madrid on Monday to demand Rubiales resign over a scandal that has made global headlines, with The New York Times saying the outcry "has come to embody the generational fault line between a culture of machismo and more recent progressivism".

Marina Subirats, former director of Spain's Women's Institute which fights for gender equality, called Rubiales a "typical male chauvinist" with the "vocabulary and gestures that go with that".

Rubiales, she recalled, had also come under fire for grabbing his crotch with both hands as he celebrated Spain's 1-0 win against England in the final while standing next to Spain's Queen Letizia.

The backlash in Spain over Rubiales' behaviour shows that the scandal will define "a before and an after", with the kiss representing "the old world," said Aina Lopez, a sociologist at Madrid's Complutense University.

- 'Paradigm shift' -

In 2004, Spain passed Europe's first law to crack down on gender-based violence which established special courts, offered free legal aid for victims, and set up a hotline that would not appear on users' phone bills.

And last year, the government reformed the criminal code to define all non-consensual sex as rape in a move responding to the nationwide outcry and mass street protests provoked by a horrific gang rape in 2016.

The backlash over Rubiales' kiss "forces society to question itself on more minor topics that violate women's dignity and to ask themselves 'should a woman accept that a man kisses her like this? Yes or no?'," added Lopez.

While Spain has become a reference in Europe in the fight against gender violence, the cross-party consensus over the issue has been broken in recent years by the rise of far-right Vox, which is overtly anti-feminist.

"It is easier to change a law than a culture," the government's top gender violence official Victoria Rosell told public radio.

But she said there had been a "paradigm shift" in recent years in the country, with women increasingly raising their voices against "those who think they have the right to women's bodies".

Subirats said public opinion was "changing in a country that has historically been very male chauvinist and which is saying for the first time: 'no, this is unacceptable'.

"It is a warning," she said.

Sports Minister Miquel Iceta said the government was determined to do away with "any obstacle" facing women in sports.

"Unfortunately this has come about because of an incident that never should have happened," he added Tuesday.