Congress president Sonia Gandhi and over 100 party leaders today walked in a large group to former Prime Minister Manmohan Singh's residence in a striking show of solidarity after a court summons to him in a coal scam case. "He is known not just in India but throughout the world as a person of integrity and probity. We offer our unstinting support and are fully behind him. We shall fight this not only legally but with all our means at our command," Mrs Gandhi, expressing outrage, told reporters outside Dr Singh's home.