In only his third news conference in a decade, Prime Minister Manmohan Singh said that Gandhi — the 43-year-old heir to India's Nehru-Gandhi political dynasty — has the best credentials to become the next head of the Congress Party and prime minister of the world's biggest democracy.
Singh is 81 and was not expected to seek another term.
"I have ruled myself out as a prime ministerial candidate," Singh said. "Rahul Gandhi has outstanding credentials. ... I do hope the party will take the right decision at the appropriate time."
Friday's news conference came at a time when the Congress Party's stock is low, battered by corruption scandals, internal feuding, and an inability to deal with a stumbling economy and deep-rooted problems with poverty, infrastructure and education.
The opposition Bharatiya Janata Party, led by Narendra Modi, has the momentum ahead of the May elections, after trouncing Congress in recent state polls. The vote was seen as a gauge of voter sentiment in the secular country of 1.2 billion.
Singh said it would be disastrous if Modi became prime minister.
Modi, chief minister of western Gujarat state for the past 11 years, is credited with turning his western state into an industrial
haven. But critics question whether the Hindu nationalist chief can be a truly secular leader over India's many cultures.
Modi has been accused of doing little to stop anti-Muslim riots in the state in 2002, which left more than 1,000 people, mostly Muslims, dead.
"Without discussing the merits of Modi, it would be disastrous for the country to have Narendra Modi as the next prime minister," Singh said.
Asked about BJP claims that he was a "weak" prime minister, Singh said: "If by a strong prime minister they mean you preside over the massacre of innocent citizens on the streets of Ahmadabad, if that is the measure of strength, I do not believe that is the sort of strength this country needs, least of all from its prime minister." Ahmadabad is the commercial center of Gujarat.
Modi has denied any role in the violence and says he bears no responsibility for the killings. Last month, he said that he had been "shaken to the core" by the violence and that his government responded to it swiftly and decisively.
The BJP was quick to hit back at Singh on Friday, saying that with corruption scandals erupting around the government, the prime minister was in no position to criticize Modi.
Singh brought "agony and misery to the country and its people because of his shameful governance," Ravi Shankar Prasad, a top BJP leader, told reporters after the prime minister's news conference.
"You are nobody to call (Modi) a disaster," Prasad said of Singh.
Singh, a technocrat, was chosen to fill the prime minister's seat in 2004 by Sonia Gandhi, the widow of assassinated Prime Minister Rajiv Gandhi. But he has been widely seen as a regent, keeping the seat warm until Rahul Gandhi was ready to take what some see as his birthright.
Singh also addressed the recent diplomatic furor between India and the United States, touched off by the arrest and strip search in New York of an Indian diplomat accused of underpaying her Indian maid.
Singh said relations with the United States are a top priority.
"Recently there have been some hiccups," he said. "But I believe these are temporary aberrations. Diplomacy must be given a chance to resolve these differences."