Eknath Shinde and Uddhav Thackeray-led factions of the Shiv Sena would be celebrating the party's foundation day at separate events in Mumbai on June 19.
The day is likely to witness a verbal duel as both factions are trying to claim the mantle of the 'true inheritor' of party founder late Bal Thackeray's legacy ahead of the next year's Lok Sabha and Maharashtra assembly elections as well as the long-due civic polls in Mumbai.
The Shiv Sena split in June last year after Shinde and 39 other party MLAs rebelled against then Maharashtra Chief Minister Uddhav Thackeray and toppled the Maha Vikas Aghadi coalition government of the Sena, NCP and Congress.
Shinde then became chief minister with the BJP's support and the Election Commission of India subsequently granted his faction the original party name and 'bow and arrow' symbol while the Thackeray group was named Shiv Sena (Uddhav Balasaheb Thackeray).
While the Shinde-led Shiv Sena will hold its event at the NESCO ground in Goregaon in northwest Mumbai on Monday, the Shiv Sena (UBT) will celebrate the foundation day at Shanmukhanand Hall at Sion in central Mumbai.
Shiv Sena (UBT) leader Sanjay Raut asserted that the Uddhav Thackeray-led group was the real Shiv Sena.
Shiv Sena MP Shrikant Shinde, the son of chief minister Eknath Shinde, said party workers from across the state will gather for the event.
Sena (UBT) mouthpiece 'Saamana' said that on Sunday, Uddhav Thackeray will speak at a party conclave in Worli in south-central Mumbai, the Assembly seat of his son and former minister Aaditya Thackeray.
Aaditya and senior Sena leader Subhash Desai will inaugurate the conclave. A film on the work done by Uddhav Thackeray during his tenure as chief minister will also be screened, a report in the Saamana said.
Leader of Opposition in the Maharashtra Legislative Council Ambadas Danve and Raut, who is a Rajya Sabha member, will also address party workers at the conclave, the Saamana added.
Bal Thackeray, a political cartoonist, founded the Shiv Sena on June 19, 1966, and made the pride of 'Marathi manoos' (Marathi speakers in Mumbai) the core plank of its politics.
As elections loom, to establish that their respective faction is the real Sena is an existential challenge for both Uddhav Thackeray and Eknath Shinde.