The former Bihar chief minister said he was still hopeful that Samajwadi Party chief Mulayam Singh Yadav and Bahujan Samaj Party (BSP) supremo Mayawati would come together.
"It is not possible in a day or two. It will take time. But I am confident they will join hands to defeat the BJP in Uttar Pradesh."
Mayawati has rejected suggestions that she should team up with Mulayam Singh Yadav to combat the BJP, which won 71 of the 80 Lok Sabha seats in Uttar Pradesh in May. Two other seats went to a BJP ally.
Lalu Prasad hinted that he would talk to Mayawati and try to convince her to change her mind vis-a-vis Mulayam Singh Yadav, who the BSP chief considers her biggest foe.
Lalu Prasad pointed out that if he and Janata Dal-United leader Nitish Kumar could team up after over 20 years, "why cannot Mulayam and Mayawati come together"?
He added: "They should come together like we have come together to defeat the BJP."