The Congress and JD(S), which are fighting the Lok Sabha polls in Karnataka in an "alliance of compulsion" after having contested the state elections against each other, face a key challenge of ensuring transfer of votes between the parties that would test the mettle of the ruling coalition.
It is even more daunting in the old Mysuru region, where both parties are considered as arch-rivals, having been at loggerheads for decades.
The Congress and the JD(S), which had bitterly fought each other in the May 2018 assembly polls, had sewed up a post-election alliance after a hung verdict with the BJP emerging as the single largest party but falling short of required numbers.
The Congress will contest 20 Lok Sabha seats and the JD(S) eight under a deal between the coalition partners finalised on Wednesday after weeks of haggling.
For the coalition to emerge as a formidable opposition to the BJP and win a number of seats, it is crucial for the Congress to transfer its votes to the JD(S), and vice-versa.
Conceding that transfer of votes is a "bit difficult" and not an easy task, senior JD(S) leader Y S V Datta said it is more so in the old Mysuru region as the Congress and his party are "common rivals" and "there is no BJP there".
"So as we have been fighting against the Congress in successive elections. Now all of a sudden Congress workers supporting our candidate and our workers supporting Congress candidate is slightly an embarrassment," he told PTI.
Datta, who is JD(S)' campaign committee chief, however, said, as this is not a local election, he didn't expect that kind of rivalry between the workers of the two parties.
"As this is a Lok Sabha election, and as Delhi is far. Whether it is Congress or JD(S) won't matter much for them (party men)... so ultimately both party workers will fight the election together," he added.
Asserting that trust is key to the success of any alliance, senior Congress leader and MLA Ramalinga Reddy said, "It is still initial stage. There will be some kind of hiccups, but gradually it will be alright and they (both partymen) will adjust."
According to the seat-sharing arrangement, the JD(S) will contest from Uttara Kannada, Chikmagalur, Shimoga, Tumkur, Hassan, Mandya, Bangalore North and Bijapur, while the Congress will field candidates for the rest 20 seats.Among the eight seats with the JD(S), it has MPs in Hassan and Mandya Tumkur is with the Congress and the rest five are represented by the BJP.
As a majority of the seats the JD(S) will be contesting are held by the BJP, transfer of Congress' votes to its regional partner is important for the alliance to outperform the saffron party.
The JD(S) will also need Congress' support in its own bastion Mandya this time, where Chief Minister H D Kumaraswamy's son Nikhil Kumaraswamy is pitted against Sumalatha Ambareesh, wife of late actor-turned-politician Ambareesh.
Mandya has become a high-stakes battle for the father-son duo of former prime minister H D Deve Gowa and Kumaraswamy, as they are facing backlash for promoting dynasty politics by fielding Nikhil. Gowda's other grandson Prajwal Revanna is JD(S) candidate from the family's home turf of Hassan.
The Congress too will need JD(S)' votes to be transferred to it in constituencies like Mysore, Chikkaballapura, Bangalore Rural among others, where the regional party has a considerable base.
In the 2014 general election, the BJP had bagged 17, Congress nine and JD(S) two seats. However, in the by-polls, the BJP had yielded the Bellary seat to Congress.
The transfer of votes will not be easy, as some in the Congress are upset over the party's decision to cede constituencies such as Tumkur and Uttara Kannada to the JD(S). Local party leaders have even threatened not to support their alliance partner in the constituency, and to contest as a rebel candidate.
With a section of local Congress leaders and workers seen supporting Sumalatha, who is likely to contest as an independent candidate in Mandya after being denied ticket, JD(S) leader and Minister Sa Ra Mahesh have warned the grand old party of repercussion in the event of any misadventure by it in the Vokkaliga bastion.
"How you (Congress) will treat us (JDS) in Mandya, the same will resonate in Mysore (where Congress candidate will be contesting)," he said at a JD(S) rally on Friday. Transfer of JD(S) votes is crucial for the Congress in Mysore. Currently, the BJP has a hold over the seat.
Meanwhile, five Congress MLAs from Bangalore North, after a joint meeting with JD(S) MLAs from the constituency on Friday, announced that they will work together for Deve Gowda's victory, if he contests from the seat.
Gowda is yet to take a call on whether he will contest from Tumkur or Bangalore North.
The JD(S) has doubts about the Congress' complete support in Bangalore North, as most of the party MLAs there are considered to be close to Siddaramaiah, and they may "seek revenge" for the former chief minister's defeat from Chamundeshwari in 2018 assembly polls, according to party sources.
Narayana A, who teaches Political Philosophy and Indian Politics at Azim Premji University, said, "It is an alliance of compulsion, in old Mysuru region. There is no doubt about it... at this stage on the transfer of votes we cannot say much, we will have to see the candidates.""Also, the kind of signals that have been going out ever since the formation of the coalition government has created some kind of confusion among the workers," he said.