He also claimed that the Congress had first come with a proposal to field vice-president Bhairon Singh Shekhawat as a consensus candidate in the election to deny a second term for incumbent A P J Abdul Kalam.

"It (Shiv Sena's decision) was an adverse turning point... the first jolt," he remarked. The decision of the Third Front, or the United National Progressive Alliance, to abstain was the second one, Advani told a group of reporters in New Delhi.

Advani's comments come a day after Former Prime Minister Atal Bihari Vajpayee reportedly told a National Democratic Alliance meeting on Tuesday that cohesion and numbers of the opposition alliance were becoming an issue of grave concern.

Unfazed by the Congress' attack on him for his party's vitriolic campaign against Patil, Advani said it was an achievement creating "serious doubts" about the UPA's functioning. The opposition was now ready for a "long haul", he added.

The former deputy prime minister, who wrote letters to voters, issued an appeal to UPA leaders to replace their candidate and petitioned the EC to declare the Third Front's move unconstitutional, however, summed up the NDA's presidential campaign as an exciting experience.

Advani, whose approach in the presidential campaign sharply contrasted with that of Vajpayee, said the BJP had initially received a proposal from the Congress to put up Shekhawat as a consensus candidate and Union Minister Sushil Kumar Shinde for the vice-president's post.

"But we saw through it (the proposal). They had no such intention. Their proposal only showed how strongly they were opposed to Kalam," he said, adding he had discussed the offer with Vajpayee.

He said the Congress also wanted a commitment from the BJP that Shinde would be the successor to Shekhawat.

Advani, however, ruled out any boycott of Patil in the event of her being elected president.

"It's not my thinking," he said in reply to a question in this regard.

On the NDA campaign, the Leader of Opposition said, "Creating serious doubts about the manner in which this government is conducting itself is not a small achievement for the opposition."

The BJP-led fight for the Presidency, he insisted, was not symbolic in any manner. "It was a difficult battle, a hard one. But it was not for symbolic reasons. Our fight was not just symbolic," he said.