The 64-year-old former Lok Sabha Speaker, whose candidature for Presidentship has divided NDA, resigned citing the "disinclination" of his party to "endorse" his nomination for the top post.
Sending his resignation letter to party chief Sharad Pawar which was immediately accepted, Sangma said he had received "promises of support from senior leaders of non-Congress parties, including those in the NDA" after backing from AIADMK and BJD.
Significantly, he sent the resignation letter soon after Subramanian Swamy, whose Janata Party a constituent of NDA, met him apparently to pledge support on behalf of the BJP-led coalition.
His resignation could have an impact on continuance of his daughter Agatha, Minister of State for Rural Development, in the government as NCP was unhappy over the move and suggested that he had gone back on his promise.
The NCP, a constituent of UPA, had already warned of disciplinary action against him if went ahead to contest the poll against Mukherjee.
Congress spokesman Rashid Alvi said his party would give no advice to NCP on what to do with Agatha, who has earlier earned the ire of her party for campaigning for her father.
More From This Section
Sangma quit NCP at a time when the NDA is divided over supporting him as the Presidential candidate. While BJP is keen to support Sangma, its ally Shiv Sena has openly refused to back him and favoured Mukherjee.
JD-U, another key NDA constituent, also has reservations to supporting Sangma. (MORE)