Hardik Patel, the firebrand leader who led the Patidar agitation, joined Congress on Tuesday in the presence of party president Rahul Gandhi.
Senior Congress leaders went to Gujarat to attend the Congress Working Committee meeting.
The important meeting, the first one to be organized in PM Narendra Modi's home state in 58 years, was called to chalk out the strategy for upcoming general elections.
Patel has been demanding a reservation since 2015
Patel has been demanding that the Patidar community should get benefits of reservation. His agitation turned violent in 2015 when a mob of about 3,000-5,000 people vandalized the office of BJP MLA Rushikesh Patel.
15 people were killed and Patel was accused of rioting.
In July 2018, a Gujarat court sentenced him to two years in prison, but he was granted bail later.
Patel joined hands with Congress during 2017 assembly polls too
Notably, Patel supported Congress during the 2017 Gujarat assembly elections as well. Announcing the alliance, Patel had said the grand old party offered an "acceptable solution" of quotas for Patidars.
Subsequently, Congress won 81 out of the 182 assembly seats.
In the crucial Lok Sabha polls, Congress is eyeing the Patidar vote share and Patel's formal entry into the party will ensure that.
Earlier, three Congress leaders left party to join BJP
Patel's much-anticipated entry into politics comes at a time when Gujarat Congress is facing a crisis.
In the last five days, three Congress legislators have ditched the party and joined BJP, hinting that all isn't well.
The leaders who left Congress are, Vallabh Dharaviya, Parsotam Sabariya, and Jawahar Chavda. Chavda was made a cabinet minister in Vijay Rupani government soon after he joined BJP.
Patel has been a staunch critic of PM Modi
In recent months, Patel grew close to senior Opposition leaders like Sharad Pawar and Mamata Banerjee.
The 25-year-old leader shared the stage with stalwarts like Farooq Abdullah, Chandrababu Naidu, Akhilesh Yadav at Banerjee's mega opposition rally in January.
While asking attendees to not vote for BJP, Patel had said that after fighting goro (Britishers) it was time to fight choro (thieves).