Chacko's challenge came a day after Rahul threatened to pursue "all legal actions" against Swamy dubbing his allegations as "utterly false, entirely baseless and defamatory".
Stepping up the attack, Chacko said, "Now the bluff master (Swamy) will face music" but refrained from giving a categorical reply whether Congress would sue the Janata Party chief as suggested by Rahul yesterday.
"Future course is open to us. All options are open to us," he merely said.
He also parried questions about the specific charges levelled by Swamy as well Leader of Opposition Arun Jaitley on the issue.
"Whether Swamy will sue or not, we want to see. It is not our responsibility. It is the responsibility of the people, who raise an allegation. We are not responsible for it. We have explained that there is no wrong thing.
"They have been doing that consistently. He is holding press conference and running away to make next allegation the next day. They are making blind allegations. They have nothing to substantiate. No newspaper's property is valued in real estate terms," Chacko said.
He said that if there is any violation of Income Tax Act or the Company Act, "we challenge them to prove it. There is no commercial transaction. People are trying to mislead and gain out of confusion".