The Congress also announced that its Lok Sabha MP from Ludhiana, Ravneet Singh Bittu, who is a grandson of former Chief Minister Beant Singh, will contest against Punjab Deputy Chief Minister and Akali Dal president Sukhbir Singh Badal from the latter's Jalalabad seat.
Congress party in-charge for Punjab Asha Kumari told the media in New Delhi on Monday that the party has cleared the names of Amarinder and Bittu for the two seats.
She said that Sidhu, a four-time former BJP MP, would contest from the Amritsar-East assembly seat.
Sidhu told the media in New Delhi on Monday that "joining the Congress was a home-coming" for him and that he was a "born Congressman".
With the Aam Aadmi Party (AAP), which is challenging the Akali Dal-BJP alliance and Congress in Punjab, already having announced its Sangrur Lok Sabha MP Bhagwant Mann and Delhi lawmaker Jarnail Singh to take on Badal junior and Badal senior from the Jalalabad and Lambi seats, the contest for these seats is poised to be a high stakes affair.
Describing Lambi as his "karam bhoomi" (place of action) from where he would "teach the Badals a lesson for the savagery and atrocities they had unleashed on the people of Punjab over the past 10 years", Amarinder Singh on Monday said he would get all cases of religious sacrilege thoroughly investigated and punish the Badals if found guilty.
Addressing a rally at Chamkaur Sahib, 50 km from here, on Monday, the former Chief Minister said Patiala (his traditional assembly seat which he is contesting again) was his `janambhoomi' (birthplace) to which he owed his emotional roots.
But he has "chosen Lambi as my karambhoomi since I owed it to the people of Punjab to teach the Badals a lesson for all their crimes and misdeeds," Amarinder said.
"The Badals have spent the past 10 years bolstering their family interests, with all the key businesses in the state owned by them and the Akali-patronized mafia ruling Punjab," Amarinder said, questioning Chief Minister Badal where he would take all the wealth he had accumulated.
Amarinder criticized the AAP leadership, particularly is national convener Arvind Kejriwal, for "their attempts to unleash anarchy in the state to promote their personal interests at the cost of the interests of the Punjabis".
Taking a snipe at Kejriwal's attempts to project himself as a Sikh Punjabi by trying to wear a turban during his public meetings and rallies, Amarinder warned the people against being taken in by his "frivolous gimmicks".
"He's a liar out to snatch power in Punjab and become the Chief Minister of the state," Amarinder said.
Elections to 117 assembly seats in Punjab will be held on February 4.
The main contest is between the ruling Akali Dal-BJP alliance, which has been in power in Punjab since 2007, the Congress and the AAP.