Senior BJP leader Arun Jaitley, in his blog post Sunday, accused the Congress party and Himachal Pradesh Chief Minister Virbhadra Singh of trying to "brazen out" allegations of corruption.
"The Congress party and Virbhadra Singh have decided to brazen out the allegations of corruption. Sonia Gandhi and Rahul Gandhi will hide behind silence," Jaitley wrote on a blog post.
The Leader of Opposition in the Rajya Sabha said: "Virbhadra Singh has dared anyone to either lodge an FIR against him or prove the allegations of corruption".
The opposition BJP in Himachal Pradesh Saturday started a week-long "Virbhadra hatao, pradesh bachao" (Save the state, remove Virbhadra) campaign seeking the chief minister's resignation after corruption charges were levelled against him.
The Congress has been defending Virbhadra Singh. Even Prime Minister Manmohan Singh evaded a question on the allegations at a press conference Friday.
Allegations, based on a newspaper's investigative report, are made that in May last year, the Himachal Pradesh chief minister received over Rs.1 crore from Venture Energy and Technologies Pvt Ltd.
A month after the money was received, it is alleged that the firm got a fourth extension in the time allowed to start construction of a hydropower project in the state's Chamba district.
The private firm also allegedly transferred Rs.60 lakh into the account of Pratibha Singh, wife of the Himachal chief minister and a Lok Sabha member.