She is known as the sphinx of Indian politics, the mysterious widow who rose to lead a nation of 1.14 billion people. Yesterday MPs loyal to Sonia Gandhi threatened legal action to stop the sale of a "fictionalised biography " that claims to have solved her riddle.

The Red Sari: When Life is the Price of Power, is already a bestseller in Gandhi's native Italy and in Spain. Written in the first person, it tells the story of the 64-year-old politician recounting her humble childhood and youth in north-western Italy, her marriage to Rajiv Gandhi, before following her political career, which culminated in the victory of the Congress party under her leadership in elections in 2004.