BJP on Monday backed former telecom minister A Raja's demand that the court make then finance minister P Chidambaram a witness in the 2G spectrum case and demanded that he should be sacked and criminal investigations be initiated against him.

"Raja has said in court that under Section 311 of CrPC, Chidambaram should be called to the witness box and asked about all the decisions taken in the 2G spectrum allocation," BJP spokesperson Jagat Prakash Nadda said.

BJP maintained that Chidambaram should clarify in court if Raja's contention is correct that all the decisions were taken after holding discussions with him.

"The UPA government is a coalition of corruption. It is not just the DMK, this whole government is deeply steeped in corruption. And Chidambaram has been involved at every stage (in 2G spectrum allocation)," Nadda said and demanded that Chidambaram should be sacked.

"Criminal investigation should be initiated against Chidambaram. He is equally responsible as Raja," he said.

BJP also demanded an inquiry into the alleged role of prime minister Manmohan Singh in the matter.

"Questions are being raised and fingers pointed at the Prime Minister also. We want free and fair investigation. The culprits should be brought to book," Nadda said.