The BJP, however, reacted cautiously saying Sena leaders only suggested snapping of ties to their chief Bal Thackeray who will ultimately take the final decision.
At a late night meeting at Thackeray's residence "Matoshri" in Bandra, majority of Sena leaders, upset over its BJP's fielding its nominee for Chimur seat in Vidarbha, were understood to have favoured breaking of its alliance with BJP in Maharashtra.
However, they authorised Thackeray to take a final decision on ending the alliance, Sena sources said.
The late night meeting at Bal Thackeray's residence was attended by senior Sena leaders including the party's Executive President Uddhav Thackeray, Manohar Joshi and Subhash Desai, party sources said.
One Sena leader Sanjay Raut, Rajya Sabha MP of the party, went to the extent of saying "Shiv Sena has split from BJP. It's our decision. We have not spoken to BJP."
The Sena chief is understood to have conveyed his unhappiness and disappointment with BJP for being adamant on the issue of fielding its candidate for Chimur Assembly by-election.
"If there is not going to be an understanding between the saffron partners over Chimur, then the situation in the state will reflect this mood," the Sena is understood to have told the meeting.
Both the saffron parties have announced they would be contesting the by-election and ruled out going back on their decision.
BJP spokesman Prakash Javadekar said, "This (snapping of ties with BJP) is not a decision of Shiv Sena. This is what they have suggested and it is for Balasaheb to take the decision. We are not going to publicly join issue with them".
Senior BJP leader Gopinath Munde said, "Nobody informed us about the Sena decision and whatever information we have is from the media. I don't think the Sena leadership will take any drastic decision unilaterally".
Raut said, "We have decided to break this alliance because we don't want to stay with BJP in Maharashtra. The decision is only because of Chimur seat. Traditionally, this seat is from Shiv Sena quota and we don't like that BJP leaders are claiming that seat for BJP".
A day after Uddhav Thackeray had said that Chimur belonged to Sena and the party would contest the by-poll. On the other hand, Maharashtra BJP strongman Gopinath Munde told reporters that his party would contest the by-poll as "ours is the only party which can take on Congress".
The reference to Congress by Munde is being seen as a signal to Sena whose candidate Vijay Wadettiwar recently quit the seat and joined his mentor Narayan Rane, a former Sena leader, into Congress which heads the coalition government in Maharasthra.
BJP is putting up Ramesh Gajbhe, a former state minister and a past winner from the seat in Vidarbha region, as its nominee.
Raut claimed Sena "...is very strong in Chimur and we've a very strong candidate in Chimur".
He accused state BJP chief Nitin Gadkari of breaking the alliance with Sena.