Speaking to the media, Singh said the BJP should sack its Delhi unit Chief Manoj Tiwari as he too is an outsider.
"They were against the purvanchalis, against the people from Uttar Pradesh and Bihar, against the people from Haryana. In short, they are against the migrants. Wherever the migrants settle, the BJP came out against them," Singh said.
He said this was not the first time that they are doing this.
"This is their ideology. Recall what happened to the people of UP and Bihar in Maharashtra and Gujarat. Not a single BJP leader came out in their support."
Singh said now they are attacking Kejriwal by saying how can he be Delhi's son.
"Those who are coming from Haryana, Bihar or Uttar Pradesh and working hard for Delhi, its happiness and development, are not Delhi's son? Are they enemies? This is your cheap and anti-migrant ideology," Singh said.
The Rajya Sabha MP added that the migrants in Delhi should understand the reality of the BJP.
"Throw Manoj Tiwari out of your party, if you have issue with migrants," he said.
Delhi is going to polls on February 8.
Vardhan had said on Thursday that Kejriwal was born in Hisar in Haryana, he was settled in Kaushambi in Ghaziabad, Uttar Pradesh. "How can he be Delhi's son?"
The chief minister has been portraying himself as the elder son of the city, who worked for his family.
( With inputs from IANS )