LUCKNOW, April 25: India's keenly fought electoral battle shifts on Monday to Uttar Pradesh, the country's most populous state that is widely expected to decide whether Prime Minister Atal Behari Vajpayee's National Democratic Alliance will return with a majority despite reports it was losing steam.

An assessment by the Intelligence Bureau, India's intelligence agency, indicated a drop in NDA's popularity, but Mr Vajpayee claimed on Sunday that he was confident of returning to power nevertheless. The other states in the fray on the second leg of Indian polls on Monday include Bihar, Maharashtra, Andhra Pradesh and Karnataka.

The first phase of the three-stage polling in Uttar Pradesh will be kicked off with the most widely observed constituency of Rae Bareli involved in a bitter and potentially violent contest involving Congress Party president Sonia Gandhi.

Her party has expressed fears of violence and booth capturing in Rae Bareli by her political opponents led by Samajwadi Party's Ashok Singh. District authorities have issued shoot-at-sight orders in the sensitive constituency that used to send Mrs Indira Gandhi to the Lok Sabha.

Now her daughter-in-law, the Italian born Sonia Gandhi is Mr Vajpayee's main challenger for the top job. Her son Rahul Gandhi is the first time candidate from neighbouring Amethi. Uttar Pradesh has 80 parliamentary seats. The first lot of 32 seats from the state will be part of the 136 parliamentary constituencies that vote on Monday.

Former Defence Minister Sharad Pawar from Maharashtra and former chief minister of Bihar, Mr Laloo Prasad Yadav, are among the prominent candidates who face voters, the second of India's four- stage electoral battle.

Mr Vajpayee himself will face elections in Lucknow on May 5, which will be the second phase of the polls in Uttar Pradesh. The last phase is on 10th May. The results are expected on May 13.

Mr Vajpayee said on Sunday he was confident of returning to power despite the perceived slump in the NDA's ratings. His Bharatiya Janata Party (BJP) says it would be open to new partnerships if it loses any of the existing allies.

Mr Vajpayee's main rival in Lucknow is his former cabinet colleague and lawyer Ram Jethmalani, who is being supported by the Congress as an independent candidate. In a joint press conference in Rae Bareli on Sunday, District Magistrate T. P. Pathak and Superintendent of Police B. R. Mina said elaborate security arrangements had been made.