Change is coming to Football Federation Australia, with pro-reform forces claiming victory at the end of a two-year struggle for power of the sport.

Steven Lowy's tenure as chairman - and his family's 15-year hold on Australian football - will end next month with the acceptance of constitutional changes at Tuesday's extraordinary general meeting in Sydney.

The decision hung on a knife edge, with state federations and a sole A-League club representative voting 8-2 to grow the FFA Congress.

One vote fewer, and it would have failed.

Crucially, the decision will stave off the threat of FIFA intervention in Australian football.

The world governing body instructed FFA to grow its Congress - one of the smallest in world football - and issued a final, blunt reminder on the eve of the key vote.

FIFA secretary general Fatma Samoura wrote to Lowy to say that FIFA "clearly anticipates that the proposed changes to the FFA Constitutions will be adopted at tomorrow's EGM".

The acceptance of the vote grows the number of Congress members from 10 to 29.

More A-League club representatives, a players' representative and a women's football voice will be welcomed to the table, with weighted voting rights.

Lowy said the transformation would change the organisation dramatically.

"A philosophical shift has taken place," he said.

"I hope for the best for the game clearly but I certainly fear for the worst.

"Our game today has crossed a red line from a corporate governance model for football to one where stakeholders with vested interests will compete for power and resources as opposed to those being decided for independent members of a board.

"This is a governance regime that I choose not to serve on ... I will not offer myself for re-election at the upcoming AGM."

Pro-reform forces, including PFA chief John Didulica, celebrated the decision, saying it would democratise the sport at long last.

"We are relieved that this issue has been resolved and a unified decision has been made," he said.

"The game's fundamentals are so exciting. Driving them forward is energising work and the players are privileged to be able to work with all parts of the sport to realise its potential."

There are still many unanswered questions - though the Socceroos and Matildas can now prepare for upcoming tournaments free of the fear of suspension by FIFA.

The new Congress should convene next month for the first time to elect new directors.

The A-League could break away from FFA control as soon as next season, with an independent body formed to run the flagship competition.

It remains to be seen what will come of the A-League expansion process, which was supposed to select two new teams to enter the competition later this month.