Mamata Banerjee won big on two fronts today. She won a legal battle against Ratan Tata that's centred on the land allotted to him in Singur. She also won her assembly by-election from her constituency of Bhawanipore by nearly 50,000 votes. She was earlier an MP. Her legal victory was declared first this morning. The Calcutta High Court ruled that the Singur Land Rehabilitation Act is constitutional and valid. The Act was introduced in June by Mamata Banerjee shortly after she was elected Chief Minister of West Bengal. It allowed her government to cancel a 99-year-lease signed with Mr Tata for nearly 1000 acres for his Nano factory. The deal had been signed by the Left which lost to Ms Banerjee in the state elections in May this year.