India's premier defended himself against accusations of inaction in a $40 billion (Dh146bn) telecoms scandal as he promised anyone found guilty in the case would be punished.
Prime Minister Manmohan Singh is accused of failing to act on allegations that his telecoms minister acted improperly and the scandal has engulfed Mr Singh, whose ruling Congress party's popularity partly rests on his "Mr Clean" image.
"There should be no doubt in anyone's mind that if any wrong thing has been done by anybody he or she or will be brought to book," Mr Singh told reporters in his first public declaration on the firestorm.
The row ignited earlier in the week when India's chief auditing body announced the botched sale of 2G telecom licences in 2008 at a fraction of their value had cost the country up to $40 billion.
Responding to the allegations, Mr Singh's office submitted an affidavit in the nation's top court.
The Supreme Court had asked the premier to "explain every attention received and action taken" on a petition filed seeking prosecution of the former telecommunications minister A Raja, who stepped down last weekend.
The Supreme Court had specifically sought a reply to accusations about Mr Singh's "alleged inaction and silence for 16 months".
The affidavit detailed how Mr Singh's office dealt with each letter submitted by Subramaniam Swamy, an opposition politician, demanding action against Mr Raja.
The submission said Mr Swamy's letters were forwarded to the justice department, which concluded that as the federal central bureau of investigation was already probing the case, any action against Mr Raja would be premature.
In a sign the pressure was beginning to take its toll, the 78-year-old prime minister who has undergone numerous heart bypasses said he "felt like a high school student facing one test after the other".
Mr Singh appealed to the opposition, which has been blocking parliamentary business all week, to allow debate to resume.
"We are ready to discuss all issues in parliament. We are not afraid of discussion," Mr Singh said. "We need to effectively deal with the threat of corruption," he added.
The Supreme Court had said Mr Singh had failed to reply to a request to approve the prosecution of Mr Raja, a low-caste politician from a regional party that is in the coalition government headed by Mr Singh's Congress.
Senior ruling party politicians have given strong backing to the prime minister, whose cerebral style and reputation for probity normally puts him above the noisy quarrels and mud-slinging of Indian politics.
Mr Singh and other Congress rulers are said by commentators to have been unwilling to risk the fall of the ruling coalition by upsetting Mr Raja's DMK party.
Mr Raja has said he is innocent and his decision to sell licences on a first-come-first-serve basis, even to companies with no telecom experience, was in line with the policy of his predecessors.