The pending by-election to one Lok Sabha and 64 assembly seats spread across 15 states and the Bihar assembly polls will be held 'around the same time', the Election Commission said on Friday.
The term of the Bihar assembly ends on November 29 and elections are likely to be held sometime in October-November.
Among the 64 vacant assembly seats, 27 are in Madhya Pradesh.
Most of these 27 seats fell vacant when rebel Congress members resigned from the party and the assembly to join the BJP.
With the resignations of the Congress members, the Kamal Nath-led government fell and the BJP returned to power.
'One of the major factors in clubbing them together is the relative ease of movement of central forces and related logistics issues,' a Commission statement said.
'Considering that General Assembly Elections of Bihar are also due and required to be completed before November 29, 2020, the Commission has decided to conduct all the 65 by-elections and the General Assembly Elections of Bihar around the same time.... Announcement of schedule of Bihar General Assembly Elections as well as these by-elections will be done by the Commission at appropriate time,' it said.
The issue of holding the by-elections came up at the meeting of the Commission on Friday.
'The Commission reviewed the reports and inputs from chief secretaries and chief electoral officers of many of the concerned states seeking deferment of the by-elections in their states in view of several factors including the extra-ordinary heavy rains in some places and other constraints like pandemic,' the statement said.
The EC took the decision after taking into account various factors, an official said.
The bypoll to the Valmiki Nagar Lok Sabha seat in Bihar has been pending.
One assembly seat each in Chhattisgarh, Haryana, Karnataka and West Bengal; two seats each in Assam, Jharkhand, Kerala, Nagaland, Tamil Nadu and Odisha; five assembly seats in Manipur and eight each in Gujarat and Uttar Pradesh are also vacant.
In July this year, the Election Commission had deferred the by-elections to one Lok Sabha and seven assembly seats beyond the six month period due to the onset of monsoon and possibilities of floods and the COVID-19 pandemic.