While addressing a public rally in Mathura, Advani lashed out at the Congress saying the party chief Sonia Gandhi wields the real power.
"From Jawaharlal Nehru till now, I have seen all Prime Ministers very closely. But I have not seen a weak Prime Minister like Manmohan Singh. I call him a weak PM because in a democracy, the most important address is of the Prime Minister, which is 7 Race Course Road, but for the first time from 2004, it is not the most important address. Now the most important address is 10 Janpath, the residence of Sonia Gandhi," said Advani.
Advani's sharp remarks came after Singh said Advani was responsible for the demolition of the Babri Masjid in 1992.
While the BJP has projected Advani as its prime ministerial candidate, the Congress has gone on record that incumbent Prime Minister Manmohan Singh would fill the top post, if voted back.
Meanwhile, BJP leader and Karnataka Chief Minister B S Yediyurappa said in Bangalore that he would file a complaint with the Election Commission against Sonia Gandhi.
"I will file a complaint against Sonia Gandhi. She came to our state and criticised the State Government, in her capacity as president of Congress party. This party has not cared for our state while it has provided 300-400 million rupees for the development of Andhra Pradesh)," said Yediyurappa.