Now, PM says he enjoyed working with Left parties

He, however, underlined that "no patriotic Indian" would annul the Indo-US nuclear deal, in an apparent message to the Left parties which have said that they would abrogate the agreement if they have any say in the next government.

"Politics is an art of the possible. Who do we reach out to and who do we not reach is a matter we can only talk about when the election results are known," Singh told CNN-IBN when asked about the possibility of the UPA reaching out to Left parties if it falls short of numbers.

"We have worked with the Left parties before, for four years they were our partners. I have enjoyed working with the Left," he said. The Prime Minister said he has "many friends" in the Left parties and named West Bengal Chief Minister Buddadeb Bhattacharya as one of his "good friends."

Significantly, Singh's soft talk on Left parties came a day after he lashed out at them, saying their policies are "retrograde" and "lack far-sightedness". At an election rally in West Bengal, he even accused the Bhattacharya government of being responsible for "under-development" of the state.

The Prime Minister also had accused the Left parties of helping the Bharatiya Janata Party indirectly by withdrawing support to the United Progressive Alliance government and pushing the Third Front which was dividing secular votes.

However, on Saturday Singh said he has "nothing personal" against the leaders of Left parties. Asked whether he would be prepared to give up operationalisation of Indo-US nuclear deal for the sake of Left support, the Prime Minister assertively responded, "There is no question of giving up the deal."

When referred to Left parties' withdrawal of support on the issue of nuclear deal last year and asked whether it was worth it, Singh said "It's definitely worth it."

He said many processes involved in the nuclear deal are still underway and only when these are completed, the benefits of the agreement would be visible. Asked whether the UPA could also approach the Janata Dal-United and the All India Anna Dravida Munnetra Kazhagam if required after polls, Singh said, "We will cross that bridge when we come to it... situation is much too fluid."