"Like in Bihar elections, all the exit polls would fall flat in Uttar Pradesh where Samajwadi Party-Congress would emerge victorious," Prasad told reporters.
"In Bihar elections in 2015, exit polls had predicted BJP-led NDA as the winner. But when EVMs were opened and votes counted, all the predictions were proved wrong," he said a day before counting.
Prasad had campaigned for some candidates of the SP-Congress alliance led by Akhilesh Yadav.
The RJD chief's version was echoed by his son and Bihar Deputy Chief Minister Tejaswi Prasad Yadav.
"As they regretted failure of exit poll in Bihar which had written off RJD in particular, the same would happen in UP," Tejaswi Yadav told reporters.
He also exuded confidence that SP-Congress would romp home after counting of votes tomorrow.