Here's your 10-point cheatsheet to this big story:
The JDU-BJP alliance will contest a total of 89 seats in this phase, with the rest allotted to NDA ally Vikasheel Insaan Party (VIP). The JDU will fight in 43 seats, the BJP 46. From the opposition alliance, the RJD will contest 56 seats and the Congress 24. Mahagathbandhan Left allies will contest the remaining 14 seats.
In 28 seats the BJP will face a challenge from RJD candidates. It will face the Congress in 12 others, with the remaining six seats will be against Left party candidates. NDA ally VIP will face RJD candidates in their five seats. As for Nitish Kumar's JDU, they will face RJD candidates in 24 seats, the Congress in 12 and Left candidates in the other seven.
Tejashwi Yadav is contesting from Raghopur against Satish Kumar of the BJP and Rakesh Raushan of the LJP. His brother, Tej Pratap Yadav, is also contesting this phase - from Hasanpur, where he faces a tough fight against two-time sitting MLA Rajkumar Rai of the JDU. Tejashwi Yadav, Lalu Yadav's political heir, has drawn massive crowds at each of his rallies so far, with promises of 10 lakh jobs, infrastructure and growth, while criticising Nitish Kumar over development and mishandling of the Covid lockdown fallout.
Voting will take place in Patna Sahib too, from where senior BJP leader and minister Nand Kishore Yadav is targeting a seventh straight win. He will face the Congress's Pravin Singh. Voting will also take place in Nalanda, which is the Chief Minister's home turf and which JDU leader Shrawon Kumar is hoping to claim for a sixth straight time. He faces Gunjan Patel of the Congress and the LJP's Ram Keshwar Prasad.
Other districts voting in this phase include Siwan, Gopalgunj and Begusarai. In the 2015 polls the RJD won 33 of 94 seats, with the JDU picking up 30 and the BJP 20. The Congress won seven seats and the LJP, which has set it stall out as an independent unit this time, with party chief Chirag Paswan repeatedly needling Nitish Kumar, won just two. The RJD emerged with around 45 per cent of the vote share. The JDU won 40 per cent.
Prime Minister Modi, who held four rallies on Sunday alone, visited Chhapra - viewed as a Lalu Yadav stronghold - and pitched the NDA's "double engine" model to counter Tejashwi Yadav's claims of poor development in Bihar. He also pounced on Pakistan minister Fawad Choudhary's comment about Pulwama to accuse the opposition of doubting the "valor of the brave sons and daughters of Bihar". He also referenced the building of a Ram temple in UP's Ayodhya and Article 370 to attack the Congress.
Both the Prime Minister and Congress leader Rahul Gandhi, who this week attacked the PM and Nitish Kumar for commenting on his and Tejashwi Yadav's family rather than talking about farmers or unemployment, will address two rallies each on polling day.
The fragile relationship between the BJP and JDU - the subject of much debate in this election - has been highlighted with the two parties largely holding separate rallies and rarely mentioning the other. At a rally in Samastipur though, the Prime Minister and Nitish Kumar shared a stage, with the Chief Minister referred to as a "friend". PM Modi said the "NDA government is being formed again under the leadership of Nitish babu". In turn, Mr Kumar, at a rally in Patna, praised PM Modi for aiding in the development of the state.
Nitish Kumar, who broke away from the NDA after Narendra Modi was named its prime ministerial candidate, only to rejoin in 2017, has been the focus of attacks by opposition leaders Tejashwi Yadav and Chirag Paswan. On Monday morning he hit back, describing them as politicians "by inheritance" and that he had "sacrificed everything for Bihar". Like PM Modi, Mr Kumar also referred to the RJD administration as "jungle raj" and said his government had been the one to establish law and order.
The third and final phase of the election - in which 78 seats vote - takes place November 7. Results for all 243 Assembly constituencies will be declared on November 10, with Nitish Kumar bidding for a fifth term. In the first, which was held October 28, voting was held for 71 seats and a turnout of around 55 per cent was recorded.
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