Mr Sinha, who joined AAP leaders as they marched to the Lt Governor's office over IAS officers "strike", said he had no regrets about not working with "small-time leaders" (of the BJP).
Expressing solidarity with Mr Kejriwal, he said, "If Atal Bihari Vajpayee were there, he would have directed the home minister to talk to the Delhi chief minister to figure out a way."
Mr Sinha, who served as finance and external affairs minister under then Prime Minister Atal Bihari Vajpayee, said he had no regrets about not working with the current BJP dispensation.
"I had an opportunity to work with Atal Bihari Vajpayee. I have no regrets about not having a chance to work with small-time leaders," he said, drawing loud cheers from the audience.
"The Centre is sleeping. There are no reports to show that Rajnath Singh is taking it seriously. Why hasn't your voice reached the PMO and the Home Ministry?" he questioned.
Mr Sinha said he tried to meet Chief Minister Kejriwal at the LG office but the police turned down his request.
The AAP government's demands to the L-G include a direction to IAS officers to end their "strike", action against those who have struck work for "four months". It has also asked the L-G to approve the proposal for doorstep delivery of rations.
In view of the protest march, police made appropriate security arrangements.
Rajya Sabha MP and senior AAP leader Sanjay Singh said that if the IAS officers give assurance in writing to end their strike and resume work, the AAP will appeal the chief minister and his colleagues to end their sit-in at the L-G office.
He said that the party would take out a candle light march tomorrow, adding that if the matter was not sorted by Sunday, its leaders and workers would stage a dharna at the Prime Minister's Office (PMO).
Sanjay Singh warned that the AAP will resort to a massive agitation if no solution is found to the existing situation.
The IAS officers' association has maintained that no officer is on strike and no work of the Delhi government has been affected.