The Boeing 737-800 plane was flying from Thailand to Muan, South Korea, on December 29 carrying 181 passengers and crew when it belly-landed at a South Korean airport and slammed into a concrete barrier in a fireball.
With the exact cause of the crash still unknown, Tuesday's unity move for a joint task force came after weeks of political turmoil, kicked off when President Yoon Suk Yeol briefly declared martial law last month.
"Our People Power Party and the Democratic Party... decided to establish a special committee," the ruling PPP said in a statement sent to AFP Tuesday.
It would "discuss the investigation into the causes" and provide support to grieving families of the dead, it said.
The opposition Democratic Party also confirmed to AFP Tuesday it has "agreed" to form a joint probe team with the PPP to look into the tragic case.
The 15-member team consists of seven from the ruling party and seven from the opposition, as well as one from neither, according to the PPP.
South Korean and US investigators are still probing the cause of the crash of Jeju Air flight 2216, which prompted a national outpouring of mourning with memorials set up across the country.
Investigators have pointed to a bird strike, faulty landing gear and the runway barrier as possible issues.
The pilot warned of a bird strike before pulling out of a first landing, and then crashing on a second attempt when the landing gear did not emerge.
Authorities have raided offices at Muan airport where the crash took place, a regional aviation office in the southwestern city, and Jeju Air's office in the capital Seoul.
It has also barred Jeju Air's chief executive from leaving the country.
Jeju Air said Tuesday it plans to cut 188 international flights departing from Busan in the first quarter of the year to improve operational safety.
The announcement comes after it previously announced its plan to cut flight operations by 10 to 15 percent by March for safety reasons.
