Congress MLA Jeet Mohinder Singh Sidhu from Talwandi Saboo assembly seat and former minister Malkiat Singh Birmi joined the SAD in the presence of party president and Deputy Chief Minister Sukhbir Singh Badal.
Sidhu, a prominent leader in the Malwa region of Punjab, once remained a close confidant of former chief minister Amarinder Singh.
Sukhbir welcomed both the Congress leaders into the party fold and described their decision as a "major development" in the Punjab politics.
Meanwhile, Assembly Speaker Charanjeet Singh Atwal said he had received Sidhu's resignation as MLA and it had been accepted.
Earlier, Congress legislator Joginderpal Jain and former minister Avtar Singh Brar had also joined Akali Dal and were rewarded with plum positions by the party.
Asked about his decision to join the SAD, Sidhu said Congress in Punjab and at the Center was on a suicidal path.
"The Congress top leaderships' non decisiveness is having a direct impact on workers in Punjab," he said, adding that state Congress Chief Partap Singh Bajwa was taking unilateral decisions like in the case of Peoples Party of Punjab supremo Manpreet Singh Badal.
Manpreet, former finance minister of the Badal government, is contesting from Bathinda against his sister-in-law and sitting MP Harsimrat Kaur Badal with the backing of Congress.
"The decision to support Manpreet by Congress is most dangerous and uncalled for by the top Congress leadership...this decision had been taken without taking Punjab Congress MLAs into confidence, particularly those from Malwa region," he said.
Sidhu said the Congress had tried to engineer defection in the PPP in the run up to the assembly polls in 2012 and now its high command is not only compromising, but joining hands with Manpreet who had tried to damage the prospects of Congress candidates in the assembly polls.
"We feel cheated and deceived by Bajwa and central leadership of Congress on the issue of Manpreet," he said.
"Everyone in the Congress wants to become a leader and no one is prepared to work as a worker," he said adding that Bajwa was unable to take workers along with him.
"The Congress is faction ridden in Punjab...Bajwa's only aim is to become the chief minister...the decision to back Manpreet is the last nail in the Congress coffin," he said.
The SAD is the largest party with 57 seats in the 17-member Punjab assembly. Its ally, BJP, has 12.
The Congress has been reduced to 44 seats with one seat falling vacant.
Image: Shiromani Akali Dal president and Deputy Chief Minister Sukhbir Singh Badal
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