In a victory for parents who have long complained about girls being forced to wear restrictive dresses and skirts, Education Minister James Merlino has vowed to ensure all girls have the option of wearing shorts or trousers.

"I am currently considering ways to ensure girls are provided the opportunity at all government schools to wear shorts and pants," Mr Merlino said.

"While the vast majority of schools already offer the option of female students wearing shorts or pants, it is something I would expect all government schools to do."

Momentum has been growing across Australia for schools to ditch uniforms that discriminate against girls and limit their movement.

Research shows that girls do less exercise when wearing a school dress.

Earlier this month the West Australian government made it compulsory for state schools to ensure girls had a choice of trousers and shorts.

The push for uniform equality has been driven by Girls' Uniform Agenda, a group of Australian parents who say forcing girls to wear dresses and skirts reinforces "rigid gender stereotypes".

Its recent analysis of uniform policies at 100 Victorian state schools revealed that one in four required girls to wear skirts or dresses.

These students become self-conscious about accidentally exposing themselves, according to group co-founder Simone Cariss.

"They are concerned about flashing their underwear when they do cartwheels," she said.

"We have girls who have to get under tables to plug in laptops and they are doing that with one hand on the back of their skirt. It's a struggle that distracts from their learning."

Ms Cariss founded the group after her daughter was barred from wearing pants at her Catholic school in Melbourne.

The school reversed its decision after Ms Cariss started a petition that has now gathered almost 21,000 signatures.

"Schools need to come into the modern era and look at what they are forcing their girls to wear," she said.

She is not opposed to girls wearing skirts or dresses to school, but said they should also have the option of trousers and shorts.

Nine-year-old Jess wears shorts to her state school every day, even in the middle of a Melbourne winter.

The Mount Eliza student finds them a lot more comfortable than dresses, particularly when she's playing sport.

"When I play basketball it is easier to bounce the ball through my legs," she said.

Her younger sister, Emma, 6, shifts between the school's trousers, shorts and dresses.

She said every school should have a uniform policy like hers.

"Girls and boys should be treated equally," she said.

In a political climate where boys wearing dresses to school was painted as one of the worst outcomes of same-sex marriage, the move is likely to raise eyebrows among some.

But those pushing for change point out that boys haven't been asking to wear dresses.

"We wouldn't have a problem with boys wearing dresses but that isn't the issue here," Ms Cariss said.

Preventing girls from wearing shorts and pants to school could amount to unlawful discrimination, according to Victorian Equal Opportunity and Human Rights Commissioner Kristen Hilton.

But she said schools had a right under the Equal Opportunity Act to determine their school uniform, although they must take into account the views of the school community.

"In 2017, when women all over the world wear pants or shorts every day, the commission would encourage all schools to provide girls with the option of choosing appropriate uniform attire, which would not be limited to dresses or skirts," she said.

Pants and trousers are less common options for girls in non-government schools.

The Alliance of Girls' Schools Australasia - whose members are mostly non-government schools - has noticed an increase in schools creating more flexible uniforms.

"The trend to include shorts and pants as uniform options for girls may be part of a school's broader gender-neutral approach," the organisation's executive officer Loren Bridge said.