More than 150 men's doubles players - including British world number one Henry Patten and the legendary Bryan brothers - have urged the ATP Tour to rethink "drastic" cuts which they believe could kill the format.
In a show of collective action, the players have written an open letter to the men's governing body as they fight proposals which would cut draw sizes and reduce prize money from 2028.
"We're at risk of losing a discipline of tennis which is historic - but has a big future," Dutch player Sem Verbeek, one of the architects of the letter, told BBC Sport.
"These proposals would destroy careers, livelihoods and dreams."
The ATP proposed halving the doubles draws at its flagship Masters 1000 events to 16 teams, with smaller tournaments reduced to eight teams.
The percentage of prize money devoted to doubles could fall from 20% to 10% - with the difference redistributed to singles players.
On Monday, a group of 137 current players, 28 legends and 20 national federations signed a letter which they hope will pressure the ATP into rethinking the proposals.
The tour's board - comprised of chairman Andrea Gaudenzi, four tournament representatives and four player representatives - will vote on them at the ATP Finals in Turin next month.
The doubles is part of a wider review by the ATP, which it says is designed to "strengthen" the tour from 2028.
The ATP aims to create "a more sustainable long-term model", insisting it wants to "maintain the important role" of doubles.
"Commercial success matters. Fairness, player welfare and the long-term health of tennis matter just as much," the players' letter says.
"Let us grow tennis together, without leaving doubles players behind."
Why is doubles under threat?
The proposals provoked an angry response from the men's doubles cohort.
British pair Lloyd Glasspool and Julian Cash, who won Wimbledon in 2025 and became world number ones, accused the ATP of trying to "kill part of the sport".
Others within tennis believe change is needed. They suggest a 20% share of the prize money for doubles is disproportionate to the interest shown by fans.
The doubles players argue the ATP should do more to promote their discipline and attract greater interest, pointing out it is the format played by most club members and therefore more relatable.
The ATP says the proposals are based on data-led analysis around costs, revenue and viewership.
With fewer singles players now competing in doubles, it believes the current size of the standalone doubles events puts severe strain on tournaments.
"We support progress. We also understand the need to grow the sport, strengthen tournaments and increase commercial value," the players' letter says.
"Still, the proposed reforms go much too far."
Might the dispute lead to legal action?
Reigning Wimbledon champion Patten recently told BBC Sport the players were facing "an uphill battle", but remained "optimistic" the tour would consider counter-proposals. Since Wimbledon there have been several meetings between both sides, including recently at the Shanghai Masters.
Many players still believe there is little appetite for negotiation from the ATP. But ATP sources insist a compromise is likely to be found.
Mike and Bob Bryan - the identical twins considered the greatest doubles pair of all-time - said they would support the group considering legal action to protect their discipline.
In 2005, the American brothers led players in a lawsuit against the ATP, when it planned radical changes to doubles.
"The tour's in the healthiest financial state it's ever been - in our opinion it should be creating more opportunities," Bob Bryan told BBC Sport in an interview at Wimbledon in July.
Mike Bryan added: "These proposed changes are anti-competitive. That's the stance we had to take in 2005. We still believe in doubles and we believe in the players fighting for this."