The squabble in Maharashtra between the Shiv Sena and the Bharatiya Janata Party  reached a peak on Sunday evening, with the Sena refusing to give its ally more than 119 assembly seats. The BJP, on its part, officially threatened to walk out of the alliance and contest all 288 seats in next month's state assembly election the Sena refuses its demand of at least 130 seats.

Adding to the pressure, smaller parties in the alliance – the Rashtriya Samaj Paksha and the Swabhimani Shetkari Sangha – have also threatened to break up with the bigger Mahayuti alliance.

The two parties have been in a political pact in Maharashtra for 25 years, but this may be their most bitter fight yet. Traditionally, the Shiv Sena has always been the big brother of the alliance, keeping a larger share of seats for itself. In 2009, for instance, the Sena contested from 171 seats, while the BJP was given just 117. But after its resounding victory in the 2014 national election, the BJP wants its due in Maharashtra.

For nearly three months now, the saffron allies have been sparring over seat-sharing for the state’s assembly polls due on October 15, with the equilibrium shifting almost every day. With the final showdown expected today, here’s a quick flashback into the history of their love-hate relationship.

The beginnings

The alliance between the parties was forged by BJP leader Pramod Mahajan and Sena chief Bal Thackeray in 1989. At that time, the Bharatiya Janata Party had been in existence for only nine years, and it had a negligible influence in Maharashtra.

The Shiv Sena, on the other hand, was going through an identity crisis of its own. When Thackeray founded the Sena in 1966, it was a political organisation that championed the cause of the local sons-of-the-soil, but did not wield any significant influence beyond Mumbai city. In the 1980s, the party seemed to be losing its relevance as support for its Marathi chauvanism weakened.

“My contention is that the Shiv Sena began to experiment with Hindutva ideas even before the BJP, because it needed a new cause,” said Sujata Anandan, author of the recent book Hindu Hriday Samrat: How the Shiv Sena Changed Mumbai Forever. But at that time, Maharashtra’s political leanings remained left-of-centre, and there were limited takers for the Hindutva ideology.

If the Sena and the BJP continued on their individual paths, the few Hindutva votes would have been divided. In the late 1980s, Mahajan saw an opportunity for the two parties to unite on the Hindutva platform, and pushed for an alliance with Thackeray.

Growing numbers

A year after they tied up, their political presence in Maharashtra skyrocketed. Earlier, the BJP and Shiv Sena were winning just a handful of seats each in assembly elections. After the alliance, even though they lost the 1990 election to the Congress, the two parties won an unprecedented 94 seats – 52 for the Sena and 42 for the BJP.

In 1995, with communal friction high in the state after the 1993 Bombay riots, the Sena-BJP alliance won and came to power for the first time in the assembly. The Sena made Manohar Joshi the chief minister, but with neither party experienced in governance, they stayed in power for just one term.

Even though they lost assembly elections for the next 15 years, the success of the alliance helped both parties expand their influence in Maharashtra. In 1999, the alliance won 125 seats; in 2004, they won 116; in 2009, undermined by Raj Thackeray’s breakaway Maharashtra Navnirman Sena, the alliance retained just 90 assembly seats. But together, they served as a consistent opposition to the Congress-Nationalist Congress Party governments, and were aware they could not generate the numbers on their own.

Constant frictions

Until his death in 2006, Pramod Mahajan was the glue that held the BJP and Sena together. “The alliance has come close to breaking up several times before, particularly because Bal Thackeray was not very fond of [BJP leaders] Vajpayee or Advani,” said Anandan. “Mahajan was always the one sweeping up the tensions and patching things up.”

After Mahajan’s sudden death, his brother-in-law Gopinath Munde took over the role of arbitrator between the parties, more out of a sense of duty towards the late Mahajan than a personal desire to stick with the Sena.

Munde, who had been the deputy chief minister during Manohar Joshi’s government, eventually forged the larger Mahayuti alliance that included smaller parties like the Swabhimani Shetkari Sangathana and the Rashtriya Samaj Paksha.

After Bal Thackeray’s death in 2012, former Maharashtra BJP president Nitin Gadkari was against continuing an alliance with the Sena’s new chief Uddhav Thackeray. Munde, however, knew that Maharashtra was crucial for the BJP at a national level, and that the state could not be conquered without support from the Sena. He resisted Gadkari’s pressure and kept the alliance alive.

End of the road?

The current bitterness between the BJP and the Sena emerged after Munde’s death in a car accident in Delhi in June. After its Lok Sabha victory, when BJP members began demanding a bigger share of seats for the Maharashtra state election, Munde was the one who was trying to relieve the tensions between the two.

With Mahajan, Bal Thackeray and Munde all dead, the Sena and BJP are lashing out at each other in an all-out war of egos. The Modi wave has given the BJP a confidence boost, and on Sunday, it officially threatened to pull out if the Sena did not concede to its 130-seat demand. The Sena, so far, says it will not budge.

One way or another, however, the battle is finally likely to end on Monday.