Spanish football federation president Luis Rubiales has resigned following fierce criticism for kissing Jenni Hermoso on the lips at the Women's World Cup victory ceremony.

The already suspended Rubiales sent his resignation to the federation's interim president, he said in an open letter, and also explained his decision to eventually step down in a television interview.

"I'm going to (resign), yes, because I cannot continue my work," the 46-year-old told television show "Piers Morgan Uncensored".

"(Family and friends) say to me, 'Luis, you need to focus on your dignity and continue your life. If not you are going to damage people you love and the sport you love.'"

Rubiales sparked a worldwide backlash after forcibly kissing midfielder Hermoso during the medal ceremony following Spain's World Cup triumph in Sydney on August 20.

After he refused to resign, FIFA provisionally suspended him for 90 days, while Spanish public prosecutors have filed a lawsuit against him for alleged sexual assault and coercion.

Hermoso, 33, had filed a complaint at the National Court on Tuesday, formally accusing Rubiales of sexual assault.

In an open letter published by Rubiales on Sunday night, he said he had informed the federation he was also stepping down as a vice-president of European football governing body UEFA.

"After the swift suspension carried out by FIFA, plus the rest of the procedures opened against me, it is evident that I will not be able to return to my position," said Rubiales in the letter.

"Insisting on waiting and clinging to it is not going to contribute to anything positive, neither for the federation nor for Spanish football.

"Among other things, because there are powers that be that will prevent my return."

Rubiales, who insists the kiss was consensual, said he did not want Spanish football to be hurt by "such a disproportionate campaign" against him.

"I have faith in the truth and I will do everything in my power so that it prevails," he wrote.

Rubiales said his departure would contribute "stability" to the 2030 men's World Cup bid in which Spain are involved.

As the pressure ramped up in recent weeks on him to quit, Rubiales' mother Angeles Bejar went on a hunger strike in protest, locking herself in a church.

- 'It's Over' -

Some Spanish politicians hailed Rubiales' downfall.

"We are with you, Jenni, and with all women," said second deputy prime minister Yolanda Diaz on social media platform X, formerly Twitter.

Spain's equality minister Irene Montero wrote "It's Over" on X, a slogan used by Hermoso and her fellow players in protest against Rubiales.

Over 80 players went on strike from the women's team in protest after Rubiales' fierce defensive speech following the incident, in which he had railed against "false feminism" and said he would not step down.

The players said they would not return until the leadership of the RFEF (Spanish football federation) was changed.

Controversial women's coach Jorge Vilda was sacked on Tuesday in the fallout from the scandal.

The RFEF, under interim president Pedro Rocha, also apologised for the "totally unacceptable behaviour" of Rubiales.

Vilda's former assistant Montserrat Tome is the new coach -- it is the first time a woman has led the team.

Spain's women's team are due to play Nations League matches against Sweden and Switzerland on September 22 and 26 respectively.

- Legal action -

Spanish prosecutors' lawsuit against Rubiales will be analysed by a National Court judge.

If the judge accepts the request, a magistrate will be assigned to head an investigation which will end either with a recommendation for the case to go to trial or be dismissed.

Australian police told AFP on Monday they were willing to help with an investigation, but that a report had not yet been referred to them.

Hermoso, who plays for Mexican club Pachuca, has said the unwanted kiss left her feeling "vulnerable and like the victim of an assault", with a statement on social media describing it as "an impulsive, macho act, out of place and with no type of consent on my part".

She has also accused Rubiales of pressuring her to speak out in his defence immediately after the furore over the kiss erupted, which prosecutors said could be considered a crime of coercion.

rbs/dj/mca/pst