A purported video of Sidhu being welcomed by a Pakistani official on behalf of Khan has gone viral in which the Congress leader is heard saying Khan was like a ''bada bhai'' to him and that he loved him a lot.
It is a serious matter of concern for India, BJP spokesperson Sambit Patra said as the ruling party seized on the issue to target the Congress.
He claimed that there was a larger design at work, and Sidhu's comments were linked to a number of Congress leaders, including Rahul Gandhi, criticising Hindutva.
Referring to Congress leader Salman Khurshid's statement in his latest book, Patra said the opposition party sees terror groups such as the ISIS and the Boko Haram in Hindutva while it finds a ''bhai jaan'' in Khan.
It is being done for appeasement politics as the Congress still believes that there is a section in India which will be happy with praise for Pakistan. There are no such people in India though, Patra added.
He noted that Sidhu had praised Khan and Pakistan earlier too and had hugged its army chief Qamar Javed Bajwa during an earlier trip to the neighbouring country.
Noting that Punjab is a border state where Pakistan tries to foment troubles, Patra said it needs a mature and patriotic leadership.
Sidhu is not right for India and Punjab deserves better than him, he said.
Pakistan's foreign minister had recently described Hindutva as a threat to global security, and he had borrowed the term from Rahul Gandhi, the BJP leader alleged.
To a question about Congress leader Priyanka Gandhi writing a letter to Prime Minister Narendra Modi on the farmers' issue, Patra shot back and asked if she also considers Khan an elder brother like Sidhu as she had in the past called the Punjab leader her brother.
Sharing the video, BJP IT department head Amit Malviya tweeted, ''Rahul Gandhi's favourite Navjot Singh Sidhu calls Pakistan Prime Minister Imran Khan his "bada bhai". Last time he had hugged Gen Bajwa, Pakistan Army's Chief, heaped praises. Is it any surprise that the Gandhi siblings chose a Pakistan loving Sidhu over veteran Amarinder Singh?'' India had recently opened the Kartarpur Sahib corridor, and a number of pilgrims from Punjab, including politicians, have visited the place on the occasion of Sikhism founder Guru Nanak's birth anniversary.