As the United Progressive Alliance marked four years in office, the Bharatiya Janata Party on Thursday dubbed Manmohan Singh [Images] as a 'lame duck' Prime Minister and dared Congress to project him as its PM candidate if it was confident that his government has performed well.

For the second day in succession, the main Opposition came out with a list of 'failures' of the government, which included 'bartering' national security for votes, 'imperilling' food and economic security and 'sanctifying' corruption.

The party used the occasion of the fourth anniversary to launch a scathing attack on the prime minister, calling him 'lame duck', 'non-performing' and 'weak' who was heading a 'squabbling cabal of opportunist parties'.

"Normally, a non-performing prime minister becomes lame duck in the last year of his tenure. For the first time, India has seen a prime minister who is lame duck from the very beginning," BJP spokesperson Ravi Shankar Prasad said.

He sought to know from the Congress whether Dr Singh will be projected as its prime ministerial candidate in the next Lok Sabha elections if it feels that the government has done so well in the last four years.

Prasad said the question arises especially when senior ministers of the Manmohan Singh Government are pitching for Rahul Gandhi [Images] as the prime ministerial nominee.