The former army officer announced his decision to quit the party on Twitter, posting a soft copy of his resignation letter on the microblogging site.
BJP national general secretary BL Santosh is likely to visit Uttarakhand soon to hold meetings on the matter.
The party had decided to 'introspect and analyse' the reasons behind the defeat in 23 state assembly constituencies in Uttarakhand including Khatima where CM Pushkar Singh Dhami contested and lost
Despite a holiday on Friday, a Division Bench of Acting Chief Justice Sanjay Kumar Mishra and Justice Manoj Kumar Tiwari heard the petition through videoconferencing.
The BSP arrived at the conclusion at a meeting of office-bearers and workers of its Uttarakhand unit with party president Mayawati here to review its performance in the just concluded assembly polls.
In a Facebook post before he left for Delhi to attend a meeting of the Congress Working Committee, Rawat, who also lost from the Lalkuwa seat, said he did not know how he would face Sonia Gandhi.
Meanwhile, Uttarakhand Irrigation Minister Satpal Maharaj and Cabinet minister Subodh Uniyal also left for Delhi while Union Minister Ajay Bhatt met senior leader BL Santhosh yesterday.
Singh, who is an MLA from Mahagama in Uttarakhand, expressed her gratitude to Congress' high command for giving the opportunity to serve the party.
Party sources said Union ministers Piyush Goyal and Dharmendra Pradhan may be sent to the state as central observers to oversee the legislative party meeting to elect the new leader.
The women MLAs who won include six from BJP, while two are from Congress. In 2002, there were four woman MLAs. It was the same in 2007. In 2012, the number rose to five.
His outburst forced Congress leader Rahul Gandhi to step in and hold frantic parleys to brought about a truce between warring factions in the party ahead of the state Assembly polls.
Chief Minister Pushkar Singh Dhami who lost his own Khatima seat announced that the new government will work on Uniform Civil Code.
Uttarakhand polls: Congress turncoats do well, daughters of 2 former CMs avenge defeat of their fathers
Former Uttarakhand Congress president Kishore Upadhyay and former pradesh mahila Congress president Sarita Arya won their respective seats of Tehri and Nainital.
Uttarakhand was then grappling with a series of problems and with elections just round the corner and Dhami ran against the clock.
BJP's Chief Minister Pushkar Singh Dhami was, however, trailing behind Bhuwan Chandra Kapri of the Congress by 954 votes in Khatima, according to trends available for all 70 seats in the state.