New Delhi, March 3 (IANS) Calling it the biggest blow to the United Progressive Alliance (UPA) government, opposition parties Thursday said the Supreme Court's decision to strike down the appointment of P.J. Thomas as central vigilance commissioner (CVC) was a victory against corruption. They also said Home Minister P. Chidambaram should resign on moral grounds.

"The home minister should resign on moral grounds. As home minister, his duty was to present the right facts but they concealed facts on the allegations against P.J. Thomas," Bharatiya Janata Party (BJP) leader Murli Manohar Joshi told reporters outside parliament.

"Even when the leader of opposition (Sushma Swaraj) brought it to their notice that Thomas' name was involved in a corruption case, they ignored it," he said.

"This is the biggest blow to the UPA government, Prime Minister Manmohan Singh, UPA chairperson Sonia Gandhi and the Congress government," BJP leader Rajiv Pratap Rudy told reporters.

Toeing the same line, Janata Dal-United leader Sharad Yadav said the step was a victory for the movement against corruption.

"The home minister should take moral responsibility and resign. The removal of CVC is a victory for the movement against corruption that is going through the whole nation," he said.

Communist Party of India leader D. Raja said: "It was a government elected CVC as the main opposition party was opposed to him, so it is a blow to the government."

Joshi added the episode would be a major lesson for the central government as well as all other governments.

"It is a lesson for this government and all governments that those on posts like the CVC and lokayuktas should be clean and there should be some standards for recruitment on such posts," Joshi added.

Thomas was selected CVC by a committee comprising Manmohan Singh, Chidambaram and Sushma Swaraj. The BJP leader had placed her opposition to his appointment on record at a meeting on Sep 3, 2010. The government, however, overruled the opposition and appointed him to the post.

The Supreme Court Thursday set aside the appointment of Thomas as CVC for his alleged involvement in a corruption case, six months after he was appointed to the post. The apex court bench headed by Chief Justice S.H. Kapadia said institutional integrity and functioning were more important than personal integrity, though both are related.

Thomas' name has surfaced in a palmolein import scam related to the time when he was a senior bureaucrat in Kerala.