World number one Novak Djokovic has resigned from his position as the president of the players council of the Association of Tennis Professionals, and is trying to form a new body to represent players, US media reported on Saturday.

He has been joined by Canadian Vasek Pospisil, who has also resigned from his position after serving for two years as the player representative for the 51-100 ranking positions.

“It has become clear that, as a player council member within the current structure of the ATP, it is very difficult, if not impossible, to have any significant impact on any major decisions made by our tour,” Pospisil wrote on Twitter.

The players are now assembled in New York’s bio-secure bubble ahead of the U.S. Open Grand Slam from Monday.

The new body will be called the Professional Tennis Players Association (PTPA) and a document detailing plans and objectives has been distributed to players, seeking their signatures.

“The goal of the PTPA is not to replace the ATP, but to provide players with a self-governance structure that is independent from the ATP and directly responsive to player-members’ needs and concerns,” the several reports quoted the document as saying.

Djokovic overcame a sore neck to defeat Spain’s Roberto Bautista Agut 4-6 6-4 7-6(0) and set up a showpiece match against Canadian Milos Raonic in the Western & Southern Open.

The Serbian did not attend the post-match news conference and organisers said he “was not feeling well on court today and it worsened after the match”.

The new venture has, however, met with stiff resistance within tennis.

The ATP currently governs the men’s professional Tour and its board, chaired by former Italian professional player Andrea Gaudenzi, is composed of representatives of both players and tournaments.

The governing body reminded the players that they have an equal say on decisions affecting the circuit.

“We recognise the challenges that our members face in today’s circumstances, however we strongly believe that now is a time for unity, rather than internal division,” the ATP said in a statement.

“We remain unwavering in our commitment to deliver for our players across all areas of our business, ensuring they receive maximum benefit from their years on Tour, and that their voices are heard.”

Roger Federer and Rafa Nadal, who make up the ‘Big Three’ of men’s tennis along with Djokovic, are also part of the council but are not in New York as they are not playing the U.S. Open.

Reacting to the development, Nadal wrote on Twitter: “The world is living a difficult and complicated situation. I personally believe these are times to be calm and work all of us together in the same direction. It is time for unity, not for separation.

“These are moments where big things can be achieved as long as the world of tennis is united. We all, players, tournaments and governing bodies have to work together. We have a bigger problem and separation and disunion is definitely not the solution.”

In April, Federer called on the ATP and the women’s WTA Tour to explore the possibility of merging while the circuit remained suspended due to the pandemic.

Federer, the most successful men’s player with 20 Grand Slam singles titles, agreed with Nadal.

“These are uncertain and challenging times, but I believe it’s critical for us to stand united as players, and as a sport, to pave the best way forward,” said the 39-year-old, who is recovering from double knee surgeries.

Besides the ATP and the WTA, the sport is also controlled by the International Tennis Federation and the boards of the four Grand Slams.

In a joint statement, the governing bodies said they have worked “tirelessly” to ensure the sport returned safely after a five-month hiatus due to COVID-19 and help the players who needed financial help during the shutdown.

“Now more than ever we need collaboration and strong relationships, and we fully support the ATP in its role in representing the best interests of players throughout this process,” it said.

Raonic said a “majority” of players was expected to sign in favour of the new association.

“Players have had plenty of time to think and reflect and take a look at certain parts which they may not be happy with and discuss,” he said on Friday.

“A lot of us were kept in the dark by our leadership for six months. We were disappointed with many things.”