"From the beginning, Congress and BJP were against this bill and that is why they didn't support the government. Both party leaders don't want the country to be corruption-free," he told reporters here.
Bhushan maintained that Aam Aadmi Party was not formed to get power, but for making India a corruption-free country.
"AAP has been formed to root out corruption from the country. Passing Jan Lokpal in the Assembly was the first priority of the AAP government. As we were not allowed to pass this bill, we did not have an option but to get out of the government," he said.
Kerjriwal yesterday resigned as Delhi Chief Minister shortly after his government was defeated on the issue of tabling of the Janlokpal Bill in Delhi Assembly in the face of a united resistance by outside supporter Congress and opposition BJP.
After the CM's resignation, the ball is now back in the court of BJP and Congress and both parties can stake claim to form the government in the national capital, Bhushan said.
"If Congress and BJP don't want to stake claim to form the government, LG has no option but to dissolve the Assembly," he said.
Asked if AAP leaders are running away from their responsibilities, he said, "Our government also wanted to implement Mohalla Sabha in Delhi. As Congress and BJP leaders were also against this model, the party cannot run government.
"Getting official posts in the government was not the motive of our party. Our party's motive is to change the system, but we are not being allowed to implement our motive, there is then no benefit to run the government," he said.
Replying to his former ally Kiran Bedi's tweets - "Did Delhi CM resign for Lokpal or Loksabha", Bhushan said she has become a BJP supporter.
Meanwhile, Congress MP Sandeep Dikshit slammed Kejriwal for stepping down as Chief Minister.
"We gave a chance to Kejriwal but he was not interested in running the government. Kejriwal has not done any positive work in his life and his party also didn't intend to run the government," he said.
The Congress MP accused Kejriwal of misleading residents of Delhi.
"Running away from responsibility is his old habit... After his resignation, we will see what the LG now decides," he said.