Amit Shah was expected to announce the BJP-Shiv Sena tie-up for the crucial polls.
BJP president Amit Shah has cancelled his September 26 visit to Mumbai, party sources said on Tuesday night, a development that comes amid delay in announcement of the ruling party's seat-sharing agreement with the Shiv Sena for the October 21 Maharashtra assembly polls.
Mr Shah, during his visit, was expected to announce the BJP-Shiv Sena tie-up for the crucial polls.
Sources in the state BJP confirmed that the scheduled Mumbai visit of Mr Shah, who is also Union home minister, on Thursday has been cancelled.
This, they said, will further delay the announcement of seat-sharing arrangement between their allies.
"Shah had especially come down to Mumbai ahead of the Lok Sabha elections and made an official announcement of yuti (alliance) between the BJP and the Sena in February this year, said a BJP leader.
"It was expected that Shah would finalise the seat-sharing formula and announce it during his visit on Thursday. With the cancellation of his visit, there is no certainty that the alliance will be announced anytime soon," he said.
Earlier, state BJP president Chandrakant Patil had said the seat-sharing deal between the parties will be announced by Chief Minister Devendra Fadnavis and Sena president Uddhav Thackeray who are discussing its contours with Amit Shah.
"The alliance talks are in the final stage. Chief Minister Fadnavis and Uddhav Thackeray are finalising the talks. They are also discussing it with BJP national president Amit Shah. I have thus decided not to make any further comments over the issue," Mr Patil told reporters.
The allies are locked in an intense negotiation on seat-sharing and a consensus has eluded them till now on how many constituencies each of them will contest.
Maharashtra has 288 Assembly seats, of which the BJP won 122 and the Sena 63 in the 2014 state polls, which they fought separately.
The Shiv Sena has maintained the seat-sharing formula was decided during the Lok Sabha elections, where the two parties had a pre-poll alliance.
According to the Uddhav Thackeray-led party, this meant equal distribution of seats and sharing of the chief minister's post for two-and-a-half years each.
Addressing a rally in Mumbai on Sunday, Mr Shah had lauded Mr Fadnavis for his performance over the last five years and asserted he will continue to hold the top post after elections, which he claimed, the NDA will win with a three-fourth majority.
Meanwhile, some opposition parties like the NCP, AAP and the Prakash Ambedkar-led Vanchit Bahujan Aghadi (VBA) have already come out with their first list of candidates.