At 5:00am Australian time tomorrow morning, the Matildas will line up against Jamaica as hot favourites to chalk up their second win of the tournament and proceed to the knockout stages.

Having pulled off the "miracle in Montpellier" against Brazil, Australia's women's side has already achieved something Australia's men's team could not — the Socceroos failed to win a game during their own World Cup campaign in Russia last year.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 29 seconds 29 s Matildas captain Sam Kerr (left) did not mince words after the win over Brazil.

For qualifying, however, the Socceroos pocketed $8 million, while the Matildas, if they make the knockout stages as most expect, will receive just $1 million.

Staggeringly, if the Matildas went on to win the entire tournament, they would receive prize money totalling only $4 million, half what the Socceroos earned for not winning a game at all.

But isn't it about revenue?

At this FIFA Women's World Cup, 24 nations are competing for just 7.5 per cent of the total prize money awarded at the men's World Cup in Russia.

Appearing on Fox Sports in the lead-up to the World Cup, Football Players' Association (PFA) chief executive John Didulica acknowledged many presumed men got paid more because they generated more revenue.

As he explained, however, FIFA's allocation of prize money to the men's and women's World Cup was not based on any such calculation.

"The obvious reaction to [the pay disparity] is that it is all based on commercial metrics, but that's not how FIFA have been calculating the amounts of prize money," Didulica said.

"For the most part, it's an opaque political process where an arbitrary figure is allocated to the tournament. What we [at the PFA] are after is greater transparency, greater accountability and for FIFA to use the World Cup as an opportunity to genuinely invest in women's football."

The long fight for equal pay

As deputy chief executive of the PFA, former Matildas captain Kate Gill has been heavily involved in Our Goal is Now, the Australian, Matildas-endorsed campaign for World Cup pay equality between men and women.

She explained the campaign began with "non-combative" aims, with the PFA and three other players' associations in Sweden, New Zealand and Denmark all writing to FIFA last year to request consultation on how much prize money would be on offer for their teams in France.

Brazil's Marta, one of the world's top players, battles for the ball with Australia's Ellie Carpenter ( AP: Claude Paris )

According to Gill, the request for consultation was ignored, with FIFA instead going ahead with its own announcement about changes to the women's prize pool.

On the surface, the result was promising: the women's prize money was doubled from 2014, while the men's pool for Russia 2018 was increased by 12 per cent.

What this actually amounted to, however, was an increase in the gender pay gap.

In 2014/15 the men's prize money totalled $343 million more than the women's. In 2018/19, the gap increased to $370m.

It's time to start a conversation

"If we were to continue with these margins it would take until 2039 to achieve gender equality in prize money," Gill said.

"The outcome we are seeking is FIFA's acknowledgement that they will engage in conversation as to what equality looks like and how we get there."

So far, however, Gill said FIFA have stayed silent on the Our Goal is Now campaign, despite some damning stats.

These include that FIFA's two top executives are paid more than the winning team of the 2019 Women's World Cup will be, and that FIFA has almost $3 billion in reserves, 66 per cent more than it budgeted to have after 2018.

Pay equality at France 2019 would reduce those reserves by less than 11 per cent.

Gill said FIFA's inaction on gender inequality contradicted its own standards to prohibit gendered discrimination.

The Socceroos receive $8 million just for qualifying for a World Cup. ( AP: Hassan Ammar )

She added the PFA and Matildas were not afraid to follow the lead of their US competitors and take the fight to the courts.

"There's no time sensitivity on this," Gill said.

"We can discuss this after the World Cup and have a candid conversation. But if they won't sit down with us, then true to their grievance procedure we will take this to the Court of Arbitration for Sport in Geneva. We have legal advice and a solid case, and we're ready to press play."

Less is not more

It's a unique situation facing a team searching for World Cup glory: the prospect of a looming legal stoush with their sport's governing body.

In this, however, the Matildas are hardly alone.

Three months ago, the 28 members of the US team filed a gender discrimination lawsuit against their own member federation (US Soccer).

Meanwhile, arguably the world's best player (and 2018 Ballon d'Or winner) Ada Hegerberg of Norway is sitting out the tournament, having quit the national team in 2017 in protest against gender inequality in football.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 35 seconds 35 s Women's Ballon d'Or winner asked to twerk on stage

While such a boycott was reportedly never on the cards for the Matildas, Didulica has said Hegerberg's situation "underscores the inequity that exists within the women's game".

"It's a terrible loss to the tournament," Didulica told Fox Sports. "To think a Messi [equivalent] would boycott the Cup because they don't feel respected … that's what we're facing at this Women's World Cup".

Prize money may not return to women's game

Making things worse, Gill said, was that the money earned at the Women's World Cup was not guaranteed to be reinvested back into women's football.

In Australia, as per their own collective bargaining agreement, the Matildas take a 30 per cent cut of any prize money earned, while the rest goes to the member federation.

That money, however, is not required to be spent on women's football.

"If I was in charge I'd want to make sure that a proportion went back to the players and the rest of that then had to be spent on women's football for that country in that developing region.

"But that's a scary reality for FIFA, because it requires transparency and responsibility."

Kate O'Halloran is a researcher at the Institute of Health and Sport at Victoria University, and is a former Victorian cricketer.