A number of BJP leaders have been left surprised at the swift turn of events in Bihar where the JD(U) has walked out of the coalition with the NDA, even though the party leadership was aware of Chief Minister Nitish Kumar's uneasiness over a host of issues.

Even until Monday, some senior BJP leaders, including those from Bihar, were of the view that the Janata Dal (United) leader was engaging in brinkmanship to pressure his bigger partner to be more accommodative.

Though there was also a tacit acknowledgement that the ball was entirely in the JD(U)'s court and Kumar was in an enviable position of dumping one ally for another, something he has already done twice since 2014 while retaining the hot seat in the state.

The BJP is likely to spell out its stand and rejoinder to the JD(U)'s charges against it once Kumar formalises the split.

Amid growing differences between the two parties, the BJP had sent its senior leader and Union minister Dharmendra Pradhan to meet Kumar a few times in recent months to defuse the crisis.

The BJP hoped that Home Minister Amit Shah's assertion at a recent meeting of the state party leaders in Patna that its alliance with the JD(U) will continue for the next Lok Sabha as well assembly polls in 2024 and 2025 will reassure the ally, which was unhappy with what it perceived as attempts from a section of BJP leaders to assert dominance and put their ally in the shade.

However, with the BJP leadership ignoring the JD(U)'s demand of a "proportionate" share in the Union Cabinet and paying little heed to the ally's complaints about the working style of some of its leaders seems to have convinced Kumar that he may continue to remain in power as part of the NDA but will have a steadily diminished authority.

Sources in Bihar said that Chief Minister Kumar has split with ally BJP for a second time in eight years and is likely to meet Governor Phagu Chauhan later in the day.

Though no official announcements have been made, senior RJD leader Upendra Kushwaha in a tweet congratulated Kumar for leading a "new coalition in new form," implicitly acknowledging the split and embracing the RJD-led `Mahagathbandhan' (Grand Alliance) to continue in office.

The meeting with Governor Chauhan is scheduled for 4 pm, said sources.