The Congress will not contest the by-elections in two Bihar Lok Sabha constituencies in the interest of unity in the United Progressive Alliance, party general secretary Digvijay Singh said.
Nalanda and Bhagalpur go to polls on November 6.
Singh said the Congress would evolve a consensus after the last date of withdrawal.
Ignoring the claim of the Communist Party of India-Marxist to the Bhagalpur seat where its nominee Subodh Roy had finished second in the 2004 Lok Sabha election, the Rashtriya Janata Dal has put up its MLA from Tarapur Shakuni Chaudhary.
Reports said the Congress wanted the seat for former assembly speaker and party veteran Sadanand Singh.
In Nalanda, though the RJD has not put up any candidate, it has so far kept silent on whom it will support.
The Lok Janshakti Party, which had emerged second in the last elections, had not entered the fray this time and wanted the Communist Party of India, which has won the seat thrice in the past, to contest.
Unconfirmed reports said that RJD leaders were toying with the idea of backing independent candidate and George Fernandes' confidante Arun Kumar in Nalanda.
LJP president Ram Vilas Paswan has, however, gone ahead and declared his support for the CPI-M in Bhagalpur and CPI in Nalanda.
