A defeat in the Delhi assembly elections, as predicted by exit polls, is bound to hit the BJP hard and shatter the aura of invincibility of Prime Minister Narendra Modi, analysts say.

Although the Bharatiya Janata Party has declared that the Delhi outcome cannot be considered a referendum on Modi's government, few think that it won't dent his or the ruling party's shine. The results of the fiercely contested election for the 70-member Delhi assembly will be known Tuesday.

Most exit polls released after Saturday's polling have said the Aam Aadmi Party of Arvind Kejriwal would win. The BJP, however, is still hopeful it will edge out the AAP.

Political analyst Aswini K. Ray told IANS that if the BJP lost the Delhi battle, its perceived invincibility under Modi will be undermined.

"(It will send out a message that the) Modi government is not invincible. The Modi juggernaut, which appeared invulnerable, is no longer invincible. It will have a major impact across the country."

A former professor of political science at the Jawaharlal Nehru University, Ray said a BJP defeat would be a personal blow to the party's president Amit Shah, considered a master election strategist.

Veteran journalist and former diplomat Kuldip Nayar agreed.

He said it was the BJP which made the election a kind of referendum on the Modi government by splashing his photograph and appeal to voters all over the capital.

Nayar told IANS that if the BJP was defeated by the AAP, it would signal that "the Modi wave has stopped".

BJP leaders themselves admit that this will partly be so because it were Modi and Shah who picked Kiran Bedi, India's first woman IPS officer, as the party's chief ministerial candidate, stunning the BJP unit in Delhi.

As a former Kejriwal colleague in the anti-corruption movement of Anna Hazare, Bedi's selection was tipped to be a "masterstroke". In retrospect, party sources say, the move failed to click with voters.

Subrata Mukherjee, who taught at Delhi University, said if the results mirrored the exit polls, the BJP may have to rethink its slogan of "Congress-mukt Bharat" (Congress-free India).

"They will realize that a Congress-mukt Delhi is working to its disadvantage," he said, because the city has been handed over to the AAP, which, like the old Congress, has a Left-of-centre outlook.

In its maiden election December 2013, the AAP stunningly won 28 seats compared to 31 of BJP and formed a government with Congress backing after a hung assembly. The AAP government resigned after 49 days.

Mukherjee said the AAP had made promises to provide cheap water and power but it will have to find resources to meet the expectations of the electorate.

"If they are in power, the law of diminishing returns will set in after a few months. Criticism will be much more than what Modi faced till now (in eight months)," he said.

A BJP loss would force Modi to reinvent himself and go for a more collective leadership rather than leave the party affairs solely to Shah, Mukherjee said.

But if the BJP wins Delhi, Modi will reign supreme.

A BJP defeat will become a wake up call for the party, added A.S. Narang, a professor of political science at the Indira Gandhi National Open University here.

Modi led the BJP to a historic triumph in the Lok Sabha election last year. The BJP then won power in Jharkhand, Haryana and Maharashtra and an unprecedented number of seats in Jammu and Kashmir.

An AAP victory in Delhi would halt the blitzkrieg.