New Delhi/Lucknow: The mother of all elections since the 2009 parliamentary battle starts in Uttar Pradesh on Wednesday, with the outcome bound to cast a long shadow on national politics.

Although only one of five states going to the polls in February-March, Uttar Pradesh's battle for ballot for 403-seat assembly has overshadowed the entire staggered balloting.

Bharatiya Janata Party (BJP) president Nitin Gadkari has called the Uttar Pradesh election a 'semi-final' ahead of the 2014 Lok Sabha polls.

With Chief Minister and Bahujan Samaj Party (BSP) supremo Mayawati facing a splintered but aggressive opposition, most pundits fear a split verdict -- and a possible coalition government.

Similar fears in 2007, however, were unfounded when Mayawati pulled off a veritable coup: she led the BSP to an outright win.

On Wednesday, 55 of the 403 assembly constituencies will see polling in the first phase, with 1.70 crore people eligible to vote.

The areas which will see balloting include Pilibhit, Lakhimpur Kheri, Bahraich, Shravasti, Balrampur, Siddharth Nagar, Maharajganj and Kushinagar along the Nepal border.

In Lucknow, Chief Electoral Officer Umesh Sinha said over 110,000 security personnel, including about 55,000 from central para-military forces and about 10,000 men of the Provincial Armed Constabulary (PAC), have been deployed at the 18,083 polling stations to ensure a free and fair poll.

He described 2,123 polling stations as 'sensitive' and 3,423 as 'hyper-sensitive'.

'The candidates include 796 men and 65 women, besides a eunuch, who is in the fray from Ayodhya,' Sinha said.

The gender ratio of voters was relatively much more balanced with about 93.36 lakh men and 79.04 lakh women, he added.

The rest of the sprawling state, India's most populous, will go to the polls over six more rounds, the process ending March 3. The votes will be counted March 6.

Although a state election, the Uttar Pradesh battle is vital for every major political party, in particular the scandal-hit Congress-led United Progressive Alliance (UPA).

A poor showing by the Congress will weaken it nationally and trip its general secretary Rahul Gandhi, who has been leading a spirited campaign across the length and breadth of the state.

He has aggressively taken on every other player -- the BJP, Mayawati and her BSP and the Samajwadi Party -- in a desperate bid to raise the fortunes of the Congress that has been out of power in the state since 1989.

The Samajwadi Party is widely considered the biggest challenger to the BSP with the potential to emerge on top in the event of a splintered vote.

The BJP, whose national growth coincided with its spread in Uttar Pradesh from the 1980s, has unleashed all its leaders in the state, barring Gujarat Chief Minister Narendra Modi.

Pundits admit that Mayawati's Dalit vote base remains as cemented as ever but it will be a miracle if she wins on her own again.

A latest opinion poll has said that the Samajwadi Party was likely to win 130-170 seats and finish on top in a hung 403-member house.

The BSP may finish with 65-105 seats, far below what it won in 2007, said the survey posted

The BJP and the Congress would be at number three and four places, winning 70-85 seats (BJP) and 55-70 seats (Congress).

Congress ally Rashtriya Lok Dal (RLD) could win 15-20 seats, it said.

The realignment of constituencies has made poll predictions difficult. Adding to the complexity in the state is the entry of the largely Muslim Peace Party that has fielded a large number of candidates.