The Congress on Sunday said the Anaj Mandi factory fire proved that the government had not learnt its lesson from the 1997 Uphaar Cinema tragedy and demanded a probe into what it called a "racket" of permitting thousands of such illegal buildings to operate with "government patronage".
Top Congress leaders expressed their condolences to the families of those killed in the fire with party chief Sonia Gandhi asking members to assist authorities in providing relief to the affected.
"Tragic loss of 43 lives in Delhi Fire Tragedy proves government has learnt no lessons from Uphaar," Congress' chief spokesperson Randeep Surjewala said.
"As lives of migrant labours become a number in an inquiry, racket of permitting thousands such illegal buildings to operate with government patronage needs to be probed," he said.
In one of the worst fire accidents in the city, 43 people were killed after a massive blaze ripped through a four-storey building housing illegal manufacturing units in north Delhi's Anaj Mandi area on Sunday morning.
In the Uphaar Cinema fire 59 people were killed and over 100 injured.
The Congress president also urged authorities of the central and Delhi governments to provide all assistance to the victims and their kin.
Sonia Gandhi expressed "deep shock and dismay" at the horrendous fire accident that has claimed several lives, the Congress said in a statement.
"Expressing her deepest condolences to the families and loved ones of over four dozen deceased in the tragic accident, Gandhi hoped that maximum lives will be saved and those injured are treated expeditiously," it said.
Congress leader Rahul Gandhi in a tweet in Hindi said saddened at the news that a massive fire in the Anaj Mandi area of Delhi has claimed many lives and left several people injured.
"I extend my deepest condolences to the families of those killed and wish for the speedy recovery of those injured," he said.
Congress general secretary Priyanka Gandhi Vadra also expressed condolences to the families of the deceased.
The news of fire in Delhi's Anaj Mandi area is very disturbing, Priyanka Gandhi said in a tweet.
"My condolences to the family and loved ones of the deceased. I wish speedy recovery to the injured. I hope that relief and rescue operations will be carried out immediately and in a smooth manner," she said.
Congress' chief spokesperson Ran deep Surjewala, general secretary organization K C Venugopal, Punjab Chief Minister Amarinder Singh, Rajasthan Chief Minister Ashok Gehlot, Deputy Chief Minister Sachin Pilot, Chhattisgarh Chief Minister Bhupesh Baghel, among others, expressed condolences to the families of those killed in the tragic incident.