He had asked Sanchez, a Socialist, in a meeting earlier on Wednesday to back him in exchange for policy pacts.
"Unfortunately, what I have obtained, as far as I understood, is a no," Feijoo told reporters after the meeting.
Sanchez did not talk to the media, but his Socialist party's spokesperson Pilar Alegria confirmed to reporters the party will not support Feijoo's premiership bid.
In a written document handed to Sanchez, the conservative candidate to premiership had said the two-year government would be extended if both parties agreed.
On Aug. 17, Sanchez's Socialists party managed to secure 178 votes with support from left-wing and regionalist parties to get its candidate elected as speaker.
Persons:
Alberto Nunez Feijoo, Violeta Santos Moura, Pedro Sanchez, Feijoo, Sanchez, Pilar Alegria, King Felipe, Vox, Emma Pinedo, Inti, Andrei Khalip, Tomasz Janowski
Organizations:
People's, REUTERS, Rights, Party, Socialist, Sanchez's Socialists, Thomson
Locations:
Madrid, Spain