New Delhi, March 17 (IANS) National Democratic Alliance (NDA) leader L.K. Advani Thursday asked Prime Minister Manmohan Singh to quit "forthwith" and said he had lost the right to govern after leaked US cables revealed that the Congress paid money to opposition MPs to win a parliament trust vote in 2008.

"The NDA demands that this government has no moral right to continue and it should quit," the Bharatiya Janata Party (BJP) senior leader told reporters here as parliament plunged into turmoil over the WikiLeaks cables carried by The Hindu Thursday.

Accusing the Congress-led government of "political immorality", the former deputy prime minister said: "UPA I survived on the strength of political sin. The PM has no moral authority or legitimacy to lead the country. He must quit forthwith."

The published US embassy cable said that an American diplomat was shown a huge quantity of money by Nachiketa Kapur, described as a political aide to Congress leader Satish Sharma, meant to be given to MPs to vote for the government.

Some MPs, Kapur allegedly told the diplomat, had already been paid money.

Advani pointed out that the 2008 parliament trust vote related to the controversial India-US civil nuclear deal that threatened to topple Manmohan Singh's government when he headed the first UPA alliance.

"The Amercian embassy was interested in the vote of confidence," the BJP leader said, and described the Congress as "a friendly party" in American view.

Advani rubbished Finance Minister Pranab Mukherjee's argument that a matter related to the earlier Lok Sabha could not be raised in the present Lok Sabha.