AAP MLA Devinder Singh Sehrawat joined the BJP on Monday, the second legislator to quit the party and join the saffron fold in less than a week.
AAP's Gandhi Nagar MLA Anil Bajpai quit the party and joined the BJP on Friday last.
Sehrawat, the party's legislator from Bijwasan, joined the party at a press conference in the presence of senior Delhi BJP leaders Vijay Goel and Vijendra Gupta.
Accusing the party of "ignoring" and "cornering" him, Sehrawat said he was not even invited to party functions.
"The party insulted me, but I took it in my stride and continued working for the development of my area," the retired colonel said.
"My people said 'we have elected you to work for us' and supported my decision to quit the AAP. I have joined the BJP considering the respect India got under the leadership of Prime Minister Narendra Modi," he said.
Goel said the BJP was interested in inducting Sehrawat into the party even before he had joined the AAP.
"The party (AAP) would ignore Sehrawat and not even invite him to events in the area. When he felt he's being insulted, the legislator decided to join the BJP," Goel said.
Kejriwal tried putting pressure on Sehrawat when he got to know of his decision to leave the "sinking ship" of the AAP, he alleged.
The BJP has kept its door open for all those who are feeling insulted in the AAP, the Union minister said.
BJP leader Vijendra Gupta said, "Kejriwal tried to conspire against Sehrawat, sidelined him...He is being made to pay for opposing the party's decision to oust Yogendra Yadav and Prashant Bhusan."
Gupta said the AAP insulted a retired Army officer and asked the party to apologise to him.
Reacting to the development, Chief Minister Arvind Kejriwal alleged the Modi government was "using the proceeds from the Rafale scam to buy AAP MLAs".
"They are doing the same thing in West Bengal. Modiji should tell how many MLAs they are planning to buy," he said.
Rejecting the charge, Goel said, "It is wrong on his (Kejriwal's) part to allege that his party MLAs are being bought by the BJP."
"We did not say anything when our former MLA Gagan Singh quit BJP to join the AAP. He (Kejriwal) should learn how to respect his MLAs. His MLAs are leaving the party due to disrespect and suffocation and not for money," he added