New Delhi, Jan 3 (IANS) Prime Minister Manmohan Singh Friday declared he will not seek a third term after the national elections in May and launched one of his sharpest attacks on the BJP's prime ministerial candidate Narendra Modi, questioning his credentials for the top job.

In a rare press conference after almost four years, the prime minister stunned everyone when he announced that he was handing over "the baton" to a new prime minister, hopefully from the UPA, after the general elections.

In his 75-minute press conference, attended by representatives of regional and national media, he showered praise on Congress vice president Rahul Gandhi whom he said had "outstanding credentials" to be the prime ministerial candidate but reserved the harshest criticism for Modi.

"Without discussing the merits of Narendra Modi, I sincerely believe that it will be disastrous for the country to have Modi as the PM," he told the media at the newly inaugurated National Media Centre here.

The BJP angrily protested his comments, saying use of such language lowered the dignity of the Prime Minister's Office.

Asked what he felt about being widely viewed as a "weak prime minister", Manmohan Singh retorted: "The BJP and its associates may say whatever they like but if by strong prime minister you mean that you preside over the mass massacre of innocent citizens in the streets of Ahmedabad, that is the measure of strength, I do not believe that sort of strength this country needs, least of all in its prime minister.

Asked about the Gujarat chief minister's statement that India will be rid of the Congress in the general elections, Manmohan Singh answered: "I sincerely believe what Mr. Narendra Modi is saying is not going to materialize."

Manmohan Singh, 81, who has been prime minister since 2004 at the head of a Congress-led United Progressive Alliance (UPA) coalition, categorically ruled out a third term, virtually signalling the end of his 17-year stint in government, 10 of them as prime minister and possible declaration of Rahul Gandhi as Congress' prime ministerial candidate.

"In a few months time, after the general elections, I will hand the baton over to a new prime minister. I hope it will be a UPA chosen prime minister and our party will work to that end in the campaign for the general elections," he announced.

"Rahul Gandhi has outstanding credentials to be nominated as (the prime ministerial) candidate, and I hope our party will take that decision at the appropriate time," he said to another question.

The prime minister said he would like to put the economy back on the growth path before he lays down office in May.

Manmohan Singh, whose government is facing a crisis of confidence, had to contend with pointed questions on his performance and leadership. He said that most of allegations of corruption had originated during the first UPA government and that the coalition had got another mandate in 2009.

BJP leader Arun Jaitley mocked the prime minister, saying the press conference was a "farce" and "intended to announce his (PM's) own farewell", while Marxist leader Sitaram Yechury said that policies pursued by UPA-II government had been "disastrous" for the country.

Janata Dal-United president Sharad Yadav said Manmohan Singh's answers were not convincing, but union minister and National Conference leader Farooq Abdullah praised him, saying he had been a good prime minister during difficult times.

Throughout the press conference, the prime minister stoutly defended his government, which faced innumerable corruption charges and allegations of wrongdoing that even led to resignation of some of his cabinet ministers.

Though he acknowledged "some irregularities", he said some of these issues had been "overstated" by the media and opposition and were "peripheral" to the core issues of governance.

Manmohan Singh said history would be kinder to him than the media or the opposition, adding he had done his best.

"I do not believe I am a weak prime minister. That is for historians to judge... Taking into account the circumstances and compulsions of coalition polity, I have done as best as I could."

"When history is written of this period, we will come out unscathed," he said philosophically.

He also admitted that rising food prices was a key reason why the Congress lost elections in Delhi, Rajasthan, Chhattisgarh and Madhya Pradesh.

The prime minister described corruption as a "monster" but "dealing with (it) is not an easy process" and needed collective effort.

He agreed that the one-year-old Aam Aadmi Party took power in Delhi by articulating people's concerns over corruption, but said "time will tell" whether it succeeds or not.

He described the Indo-US nuclear deal as his best moment.

Speaking on the dual centres of power, he said it worked "exceedingly well" and there were no hiccups in his relationship between the Congress party chief Sonia Gandhi.

Asked about his retirement plans, he said: "I have to complete my tenure and will think of it when I cross that bridge."

The prime minister, who was born in Gah in that part of Punjab that is now in Pakistan, also said he "would very much like to go to Pakistan".

He underlined that he has five months left to finish his job and has three unfinished agendas - generating jobs in the manufacturing sector, controlling inflation and keeping food prices under check and combating corruption.