It is being seen as an extension of bonhomie between the two parties after Chief Minister Nitish Kumar's support to demonetisation and which got strength after Prime Minister Narendra Modi's effusive praise of Kumar during Prakash Parva.
JD(U) ally Congress and some other parties expressed displeasure over the invitation to BJP.
Invitation to BJP for 'Dahi-Chura', the first since 2013 when JD(U) severed ties with the saffron party, has set the tongue wagging in political circles.
The JD(U) feast would be held at the residence of Bihar party chief Basistha Narayan Singh.
"Since its an auspicious occasion, I have invited everybody in the 'bhoj' irrespective of political affiliations," Basistha Narayan Singh told PTI today.
Sushil Modi, who skipped the Makarsankranti feast hosted by Prasad today, told reporters that he would attend the 'bhoj' organised by Basistha Narayan Singh tomorrow.
The senior BJP leader gave strength to media speculations over display of bonhomie between former allies BJP and JD(U) that started from Nitish Kumar's support to demonetisation and peaked after PM's praise of Kumar.
He said, "During Makarsankranti, the sun changes direction from South to North. Like change in weather, change in politics could never be ruled out. Who knows what will happen tomorrow?"
On inviting Modi, Basistha Narayan Singh said, "Its a social gathering to promote 'sadbhavna' (harmony) and no political meaning should be derived from it."
"Bihar is witnessing a rare display of unity among all parties over passing of new Excise Law, 2016, and all parties deciding to participate in human chain on coming January 21 to express strong commitment to prohibition. We wish to further strengthen this sadbhavna," Singh said.
But, Congress is not impressed.
"Had it been some personal occasion like marriage, it could be understood. But inviting BJP in a political feast is something only JD(U) can explain," Choudhary said.
He was non-committal over attending the feast and said tomorrow he would go to Siwan.
Rashtriya Lok Samata Party (RLSP) chief and Union
Minister of State for HRD Upendra Kushwaha, an ally of BJP, reminded that Chief Minister Nitish Kumar had cancelled a dinner to be hosted in honour of BJP leaders in the past.
The cancellation had taken place in February 2014 when BJP and JD(U) were in alliance and during the national executive meeting of the saffron party.
On not attending 'Dahi-Chura' feast thrown by Prasad, Sushil Kumar Modi said, "Instead of extending the invitation by himself or through any of his family members, he (Prasad) asked his PA to telephone me for the feast. When his PA is inviting, my PA will attend it."
"He keeps saying that I (Sushil Modi) was his secretary during days of Patna University students union. Is it justified that a president does not talk directly to his secretary," Modi said and claimed that it showed "the RJD chief did not want us to attend his feast."
Except for BJP, prominent leaders of Grand Alliance government participated in the feast hosted by Prasad at 10 Circular Road residence of his wife Rabri Devi.
Chief Minister Nitish Kumar, Assembly Speaker Vijay Kumar Chaudhary, Chairman of Legislative Council Awdesh Narayan Singh and Congress state chief and minister Ashok Choudhary attended the feast.