Saturday's election to the Rajya Sabha carries special weight. Unlike the Lok Sabha, which is voted in once every five years, seats in the upper house are filled on a rotational basis: a third of the members are elected every two years by legislators of the state assemblies. The Bharatiya Janata Party has a clear majority in the Lok Sabha but is still a minority in the Rajya Sabha. While the election won’t convert the BJP into a majority party, it could make its life easier, given that the saffron party's share of members in the state assemblies has been on the upswing since 2014.

Here are some of the more interesting battles.

Karnataka

This is easily the most salacious contest, given that television sting operations purportedly showed MLAs negotiating for money in exchange for their votes in election to four Rajya Sabha seats from the state. For a bit, it looked like the Election Commission might even cancel the Karnataka elections. However, it decided to go ahead with them at the last minute.

Of the five candidates battling it out for four seats, Nirmala Sitharaman of the BJP as well as Oscar Fernandes and Jairam Ramesh of the Congress will make the cut easily. The real battle remains between KC Ramamurthy of Congress and BM Farooq of Janata Dal (Secular). So scared is the Congress of losing the fourth seat that it took 10 independent MLAs, who had pledged their vote to the Congress, on an all-expenses trip to the Marriott hotel in Mumbai so that they would be unable to confer with opposition parties.

Uttar Pradesh

The state has 12 candidates battling for 11 seats with a wild card in the race: Preeti Mahapatra. Continuing a long-standing Rajya Sabha tradition of moneybags contesting the election, she is the wife of Mumbai-based businessman, Harihara Mahapatra, who once announced an ambitious plan to construct the country’s tallest building in Khajod, Gujarat. Mahapatra made a surprise entry, filing her papers on the last date before nominations closed.

Like Vijay Mallya’s Rajya Sabha election from Karnataka in 2010, Mahapatra has received support from top politicians across party lines. While filing her nomination, Mahapatra was flanked by influential state politicians such as the BJP's Suresh Khanna and Radha Mohan Das, and former Bahujan Samaj Party coordinator Jugal Kishore.

Haryana

The BJP has supported Zee television owner Subhash Chandra but it doesn’t have enough votes to get him elected on his own. But since the anti-defection law doesn’t apply in the Rajya Sabha polls, there's a chance that Chandra could pull in votes from parties such as the Congress and the Indian National Lok Dal. For what it’s worth, his own channel Zee News ran a news article on June 3 headlined, “Dr Subhash Chandra confident of victory in Rajya Sabha polls from Haryana."

Rajasthan

The BJP, with 161 members out of 200 in the Assembly, is perched comfortably with three of its candidates – Venkaiah Naidu, Om Prakash Mathur and Harshvardhan Singh – coasting through. The party’s fourth candidate will need three non-BJP votes and is pitted against the Congress-supported independent Kamal Morarka, a former Union minister and businessman.

Rajasthan wasn’t Urban Development Minister Venkaiah Naidu’s first choice – it was Karnataka, a state he represents in the Rajya Sabha now. He was forced to shift to Karnataka though by a social media campaign which accused him of neglecting Karnataka in favour of his home state Andhra Pradesh. Titled “Venkaiah Sakaiah” (Enough of Venkaiah), the campaign pointed out that Naidu failed to learn Kannada, spent his MP funds on Andhra Pradesh and spent his time in the Rajya Sabha looking after Andhra interests – a rare example of a state’s interests trumping party high command diktat in a Rajya Sabha election.

Madhya Pradesh

With three seats and four candidates, the most prominent face here is the BJP’s MJ Akbar, a former newspaper editor with his hometown in Kolkata. The Congress has one candidate, lawyer Vivek Tankha who had some tense moments as the BJP decided to play spoilsport and prop up an independent candidate Vinod Gotiya. Tankha is falling short by just one vote and he has accused the BJP of trying to break the Congress. But things now look under control as the Congress pulled out all stops with senior Congress leaders and former Union Ministers Kamal Nath and Sushil Kumar Shinde camping in the state to ensure Tankha’s victory.

Further reading: How does counting in single transferable voting system such as in Rajya Sabha and Legislative Council elections take place?
And how do so many industrialists get into the upper house?