The growing political crisis has cost Prime Minister Atal Behari Vajpayee two cabinet ministers and raised calls for his government's resignation.
Foreign Minister Jaswant Singh has been given the additional job of defence minister after the resignation of George Fernandes.
Mr Fernandes resigned after the release of video footage by an Indian website showing defence ministry employees apparently accepting bribes from journalists posing as weapons dealers.
The growing political crisis has cost Prime Minister Atal Behari Vajpayee two cabinet ministers and raised calls for his government's resignation.
Opposition leader Sonia Gandhi met with leaders of her Congress Party to plan a strategy to bring down the government.
But the government is defiant in the face of opposition challenges.
"If the opposition thinks we do not have a majority let them move a no-confidence motion. Everything will become crystal clear," Mr Advani said.
'Intimidation'
The head of the Indian media company Tehelka.com, Tarun Tejpal, accused the government of trying to link it to Pakistan's spy agency and organised crime networks.
"We are being targeted" by the prime minister's office, Mr Tejpal told reporters at a news conference on Saturday.
He told the BBC that the government seemed to be focusing on trying to discredit his company rather than investigating the issues thrown up by his reporters' undercover investigation.
Mr Tejpal said he had made his company's financial affairs public, including everything there was to be known about his employees.
Opposition
Mrs Gandhi accused Prime Minister Vajpayee of trying to defend colleagues implicated in the scandal and demanded the resignation of the government.
Observers say that the BJP, which heads the ruling coalition, is planning to counter the damaging revelations by saying they are part of an international conspiracy.
Mr Vajpayee made an unprecedented address on national television on Friday, announcing that he was ordering a probe into the allegations.
He appealed to opposition parties to end protests which have disrupted proceedings in parliament.
On Friday, the government said Mr Fernandes would be reinstated as defence minister if he was cleared by the investigation.