The Janata Dal-United (JD-U), Rashtriya Janata Dal (RJD), Congress and the Nationalist Congress Party (NCP) have decided to campaign jointly for the upcoming Bihar assembly polls from August to counter the BJP-led NDA.

The decision was taken after JD-U president Sharad Yadav met Bihar Chief Minister Nitish Kumar and RJD chief Lalu Prasad here and discussed the likely strategy of the grand alliance against Bharatiya Janata Party-led National Democratic Alliance (NDA) for the uncoming polls.

"We have decided that grand alliance of JD-U, RJD, Congress and NCP will campaign together or jointly against the BJP-led NDA," state JD-U president Vashisht Narain Singh said here on Sunday.

Lalu Prasad and Nitish Kumar, after a hiatus of 20 years, came together for a poll campaign in Bihar last year during the assembly by-polls.

In early July, Nitish Kumar's ruling Janata Dal-United launched 'Har Ghar Dastak' (knock on every door) campaign to reach out to millions of voters ahead of the coming state assembly elections.

Nitish Kumar - who was declared the chief ministerial candidate of the JD-U, Rashtriya Janata Dal, Congress and NCP combine - launched the campaign here and state JD-U leaders and workers kick-started it simultaneously from 10,000 locations across Bihar.

The door-to-door campaign is the brainchild of Prashant Kishore, Prime Minister Narendra Modi's erstwhile key strategist during the last Lok Sabha polls. Last month, Nitish Kumar launched a high-tech 'Badh Chala Bihar' (Bihar moving forward) initiative to directly reach out to the masses and seek their ideas and suggestions for the state's development. That move too was credited to Prashant Kishore.