At his maiden roadshow here, Kejriwal claimed he was in possession of a letter purportedly written by Modi recently to the Centre, asking for such a hike.
"The motive behind hike in prices of gas by three times was to extend benefit to Ambani as he owns wells of oil," he said adding that "by hiking gas prices the cost of fertilisers too will increase and this will lead to inflation and ultimately Ambani will be benefited."
The roadshow, lasting around five hours, was to garner support for AAP candidate Gul Panag.
Kejriwal took a dig at both BJP and Congress accusing them of working for Ambani.
"Both Modi and Rahul use aircraft of Ambani to travel... they extend benefits to Ambani," he said.
Sharpening his attack against Ambani, he claimed that the industrialist funded both Modi and Rahul during polls.
Hitting out at the BJP's prime ministerial candidate, he said that there was no Modi wave in the country.
"I have travelled several places...I didn't see Modi wave ...this illusion is a creation of media," he said.
On Modi's decision to contest from two seats, he said, "This shows he is afraid and not confident of winning polls."
He also accused Haryana Chief Minister Bhupinder Singh Hooda of "acquiring lands of poor farmers" and giving it to Ambani and Vadra (son-in-law Sonia Gandhi).
"I raised the land scandal involving Vadra 18 months back," he said questioning as to why BJP refrained from raking up the issue.
Hooda government was in news last year for alleged allotment of land in upscale regions of the state, including Gurgaon, favouring Vadra.
Claiming that there was no development in Gujarat as being propagated by Modi, Kejriwal said the condition of farming community in the state is "pitiable".
"Land is snatched from poor farmers and handed over to Ambani and Vadra by Modi and Hooda," he said.
Hitting out at Congress candidate Pawan Kumar Bansal, Kejriwal made reference to 'Railgate' scandal and alleged that the MP took money through his nephew.
"Bansal is a corrupt man...don't vote for him rather ensure that he loses his security deposit in the polls," he said.
Taking a dig at BJP candidate Kirron Kher, he said that "Chandigarh is not her family fiefdom. Kirron says that she is here as she wants to put the Chandigarh seat in the kitty of Modi ...Chandigarh is not her family fiefdom," he said.
"Politicians need to serve and not to put seat in someone's kitty," he said.
"Both BJP and Congress are in collusion for their political vested interests... there is hotchpotch between the two parties," he alleged.
Taking a dig at BJP in Haryana, he said that the party had fielded at least seven defectors from the Congress at the hustings.
"There is no difference between 'lotus' (BJP's election symbol) and 'hand' (Congress election symbol)," he said.
On Modi calling him a Pakistani agent in a rally at Jammu recently, Kejriwal said he should talk about issues that are important in the polls.
Kejriwal said AAP is a God's creation.
"AAP is God's creation... it is (AAP) is a God's miracle... we won 28 seats in Delhi polls with just one year in politics," he said.
"AAP is not contesting Lok Sabha polls for only getting seats in Parliament," he said adding that the party is bringing out truth of politics of the country.
On his brief tenure as chief minister of Delhi, he said that "both BJP and Congress colluded to bring down the AAP government."