The decision by the Thai Premier League (TPL) executive board to expand the competition to 20 teams this year was greeted with giants Buriram United and Chonburi giving up their seats on the committee yesterday.
BEC Tero Sasana, red, in action against Buriram United in a Thai Premier League match last season.
The TPL executive board met yesterday at the Football Association of Thailand headquarters with TPL chairman Ong-arj Kosinkha presiding over.
Also present among others were representatives of TPL sides Buriram United, SCG Muang Thong United, Chonburi, BEC Tero Sasana and Ratchaburi.
After three-hour deliberations, TPL general manager Phairit Tandpairee announced: "The meeting approved with a non-unanimous vote to increase the number of TPL teams from 18 to 20.
"BEC Tero Sasana have filed a suit with the Administrative Court with its decision pending. In case the court decides in favour of BEC Tero and we continue with 18 teams, the TPL could be sued.
"In our regulations, there is an option which allows for an increase or a decrease in the number of TPL teams if there are major happenings."
Phairit added: "Teams that will play in the TPL next season will of course include the top-16 ranked teams at the end of the 2015 season.
"This new development means that BEC Tero Sasana will remain in the TPL and there will be two promoted teams from League One -- Police United and Pattaya United.
"The remaining two teams will include one from the TPL -- either Port or TOT SC. The committee has yet to finalise a criteria to relegate one of these two clubs. It could a play-off, we don't know yet.
"The last TPL team will be one of the two League One clubs, Sukhothai or Nakhon Pathom United. Their case is also being considered by the court.
"Right now, our legal department is looking at ways of finding a solution and everything should be finalised before official draw at the end this month."
At the end of last season, BEC finished third from last and were relegated along with Port, who were second from last, and bottom club TOT.
However, BEC filed a complaint with the Administrative Court, arguing that they should get three points from a controversial match.
BEC lost 1-0 to Bangkok United but the Fire Dragons claimed their opponents used more than the permitted number of foreign players.
Saraburi finished the season just above BEC Tero.
During yesterday's meeting, Chonburi deputy chairman Annop Singtothong and Buriram United deputy manager Sirichai Kimoto staged a walk-out from the meeting room before the discussions were over.
Annop told reporters: "I have decided to quit the TPL executive board because during the meeting they wanted to increase the number of teams to 20 and I disagreed with this.
"This is because the decision will have a major impact on the planning of all TPL teams and it will affect the fans as well. I don't wish to discuss this issue much at the moment.
"I have a feeling that the approval had all been discussed and agreed before the meeting.
"The most important thing is that many of those on the board have nothing to with the teams at all. I don't understand how can they come and cast vote today.
"So if they are going to increase the number of teams in TPL to 20, they can expect opposition from us. We will be discussing this matter with other teams as well."
Apart from playing in domestic competitions, both Buriram United and Chonburi will also take part in the AFC Champions League this year.