The prime minister did more than was required in the interest of probity on the 2G spectrum scam allegations, a government affidavit to be filed in Supreme Court on Saturday will argue, as the Centre and the Congress on Friday launched an aggressive defence of Manmohan Singh.
Congress chief Sonia Gandhi said graft afflicted the broad polity of India, suggesting the problem was not limited to the Congress.
"Graft and greed are on the rise," she said at a public event attended by the PM.
Party general secretary Rahul Gandhi denied the PM was in an embarrassing position while telecom minister Kapil Sibal hopped between TV channels to defend Singh.
Sources said Sibal was told on Friday to frontally challenge the Opposition charges after the SC questioned the PM's delay in responding to Janata Party chief Subramaniam Swamy's plea seeking sanction to prosecute former telecom minister A Raja.
"We are absolutely clear we've done no wrong. The PM is a man of integrity. I don't think anyone believes he was trying to circumvent the law," Sibal said.
The aggressive defence came amid growing political speculation over why the PM and Congress leadership remained silent, fielding only spokespersons to defend Singh against the Opposition attacks.
The defence will be equally strong in the affidavit. In it, the government will state the PM was not obliged to respond at all to Swamy's plea.
It will argue that the sanctioning authority - the PM - needs to decide on such requests only if they come from prosecuting agencies, government sources said.
It will say that by seeking the law ministry's views and eventually responding to the plea, the PM in fact did more than legally required of him, and this too in the interest of probity.
The next hearing in the case is scheduled for Tuesday.