He said NDA lost the elections because of anti-incumbency against state governments and party candidates - 90 sitting BJP MPs lost - and caste polarisation.
Breaking his silence for the first time after the NDA lost power, Advani stressed that for BJP, the ideology of cultural nationalism and Hindutva gave it strength.
"Our ideological struggle will continue against those who seek to project it narrowly."
On the two catchphrases, Advani said, "These phrases, though valid in themselves, were inappropriate for our election campaign... By making them verbal icons of our election campaign, we gave our political opponents an opportunity to highlight other aspects of India’s contemporary reality - poverty and uneven development, unemployment among the youth, problems faced by the farmers - which questioned our claim. The viciously negative campaign of Congress and Communists, replete with falsehoods, prevailed over the positive campaign of the NDA."
The former Deputy PM, who is all set to take over as leader of the Opposition, also admitted that the election results had caught the party off-guard.
He, however, added, " I would like the Congress-led coalition government not to misread the people’s fractured verdict as a decisive mandate for any alliance, much less for any single party and certainly not for any individual. The message in the verdict is that people expect the new government to follow the path of maximum consensus, not only within the ruling alliance but also with the Opposition."
The BJP, he said, should self-introspect and objectively analyse the reasons for the setback. But, he stressed, there was no room for " self-flagellation". " Our future is bright...and we shall return to power."
Asked whether he considered Congress president Sonia Gandhi’s decision not to accept the prime ministership as an " act of renunciation", he said, " No, it came as a big relief to the country."
On whether the verdict has settled the foreign origin issue forever, Advani said, " Our viewpoint is very clear that people of foreign origin should not occupy constitutional posts. It is a political issue, not a personal one."
On the induction of chargesheeted ministers in the Congress-led coalition, Advani said, " While for the sake of political expediency, there have been instances of condoning crime and criminals, it is for the first time that a government has had to reward crime and criminals."
On the party’s electoral defeat, he said, " In some states, we suffered along with our allies. In others, we suffered because we dropped alliances. In urban constituencies, where we fared poorly, the turnout of our supporters was low. In some states, our organisational weakness contributed to our setback."