While backing Mr Musharraf's statement, Mr Soz told news agency ANI, "Musharraf said Kashmiris don't want to merge with Pakistan, their first choice is independence. The statement was true then and it remains true now. I say the same but I know that it is not possible."
The former union minister has said that the centre should hold talks with Pakistan "just like Atal Bihari Vajpayee and Manmohan Singh had discussions with Musharraf" as the solution lies in dialogue.
"Unfortunately, Musharraf went out of the system. He wanted dignified peace with India," he said.
He even suggested an "open dialogue with the Hurriyat Conference", which is an alliance of secessionist parties and leaders.
Mr Soz has reportedly spoken at length on this and much more in his book "Kashmir: Glimpses of History and the Story of Struggle" which is expected to release next week.
The Congress has, however, distanced itself from Mr Soz's statements. Senior Congress leader Randeep Surjewala clarified that the party has "rejected his comments". "The Congress party's stand on Jammu and Kashmir is well known. The state is a part of India."
BJP national spokesperson Sambit Patra is "shocked" and wants Congress president Rahul Gandhi to clarify if "this is the way you stand for India or are you standing against it?"
Union Minister Ravi Shankar Prasad blamed Mr Gandhi and his mother Sonia Gandhi for "encouraging anti-India forces".
"Kashmir is a critical issue. The separatists and terrorists have hijacked the growth, development, and peace in Kashmir. We all must come together to defeat such powers. One should not make such statements that will boost the morale of separatists and terrorists in the Valley," Mr Naqvi said.
The Shiv Sena which disagrees with the BJP on most issues, is on the same page with its ally this time.
"The Congress president needs to reply on Saifuddin Soz's statement and if Congress vouches for his statement. If he has so much affection for Pakistan and Musharraf, he should consider migrating to Pakistan," Shiv Sena leader Manisha Kayande said.
This is not the first time that Mr Soz has triggered a controversy. Last year, he had said that he would have kept Hizbul Mujahideen terrorist Burhan Wani alive if it was in his power. Wani was not killed by security forces in 2016.
He has also blamed India for the unrest in Valley and said the problem in Kashmir is created by India not by Pakistan.
(With inputs from ANI)