Image copyright Getty Images Image caption Leggings are no longer reserved for the gym

A letter written by a mother concerned by the number of women wearing leggings on a university campus in Indiana has sparked backlash and protests.

"I'm just a Catholic mother of four sons with a problem that only girls can solve: leggings," Maryann White wrote in a letter published in the student newspaper.

Ms White explained that the sight of leggings "obtruded painfully" on her during a visit with her four sons, and made it "difficult for young guys to ignore" women's bodies.

She notes that while attending a Mass service at the Catholic university with her family, a group of women in front of her wore "snug-fitting leggings" and "short-waisted tops".

"I was ashamed for the young women at Mass," Ms White wrote. "I thought of all the other men around and behind us who couldn't help but see their behinds."

"Think of the mothers of sons the next time you go shopping and consider choosing jeans instead," she suggested to the female students of the University of Notre Dame.

The letter sparked an immediate backlash from students, who argued that their choice of clothing should not be policed and women should be free to wear what they want.

A student group, "Irish 4 Reproductive Health", organised "Leggings Pride Day". It encouraged people of all genders to wear their leggings proudly on campus.

The event was designed to protest against the "age-old sexist trope" that women are responsible for the actions of men, who are characterised as incapable of controlling themselves.

A number of students shared photographs of themselves wearing leggings to social media as part of the protest.

For some students wearing their leggings around campus was nothing new, however the row encouraged others to don spandex in public for the first time.

Women wearing leggings and yoga pants away from the gym has become more common in recent years, and the garments have been the focus of a number of controversies.

While some online have questioned if the letter was the work of a troll, intent on stirring up controversy, the Washington Post pointed out that it is not the first time a letter to the student paper has questioned the way female students dress.

In a letter titled "Ladies, be decent", a then student railed against the "inappropriate" outfits women wore on campus.

Nicole Waddick, a senior at the university, said she chose to take part in the protest because "what I wear is not an invitation to sexualise my body".

Kate Bermingham, a PhD candidate at the university shared a photograph of herself wearing leggings along with a reminder that women of colour are more likely to be chastised for violating perceived dress codes.

Indeed, a report from the National Women's Law Center found that black girls were reprimanded more harshly than white girls for school dress code infringements.

A number of people on social media pointed out that it was "inspiring" to see so many male students supporting the protest.

One male student wrote a follow-up letter to the paper urging his female classmates to "wear what you want".

"How you dress for Mass is not a reflection of your character, nor does it disqualify you from dignified and respectful treatment from the rest of us," he wrote.