The QED leader, who is currently lodged in Agra jail on charges of murdering a BJP MLA, conveyed the decision through his brother and national party president Afzal Ansari in Varanasi. The decision was taken "to strengthen secular forces and avoid division of votes", Afzal Ansari said.
Mukhtar Ansari will, however, contest from the Ghosi parliamentary constituency in Mau district.
"We will discuss our future course of action later. Now SP, BSP and AAP have to decide how to defeat Modi," the (QED) president said.
As a BSP candidate, Mukhtar Ansari went down fighting against the BJP's Murli Manohar Joshi in 2009 by just around 17,000 votes. His entry into the contest was earlier being considered to make the high-profile poll battle in Varansi acutely polarised.
Now, in Mukhtar Ansari's absence, the Muslims votes are likely to consolidate behind the Congress candidate from Varanasi, Ajay Rai.
The QED's decision not to field Mukhtar Ansari from Varanasi comes in the backdrop of a popular perception among Muslims in the region that the Mau based don has entered some sort of a 'political agreement' with the BJP for division of Muslim votes in Varanasi.
The Varanasi unit of the party is also believed to have conveyed to Afzal Ansari that Mukhtar Ansari is losing ground to Rai in the constituency.
(With inputs from PTI)